There are plenty of posts and I'm not going to read them all.
Against my better judgement I have made some suggestions of supplements that may help with fatigue (if you don't read anything else read about sulbutiamine), they are at the bottom. I'm putting this hear because I don't expect you to read it fully as you may well disagree with it. I'd urge you to read it and hell I want you to do what it says but you should do what you think is best. However read it, at least give an opionion a chance 
I did get a general sense that a lot of them were recommending supplements and other non-evidence based treatments. I strongly advocate an evidence based approach to the problem. My advise would be drop all the probiotics, special diets and what ever else, unless they are clinically indicated...avoiding lactose due to being lactose intolerant for example. I'm pretty sure nobody will read past this paragraph now, haha.
I also saw you were pushing for an MRI. Tell a radiologist where and what to look for and he can find a tumor the size of a grain of sand (well...a bit bigger), tell him you are looking for anything weird, unless you have a massive tumor or a lesion the size of the grand canyon he isn't going to find anything...not that I suspect there is anything to find with an MRI. So I think its a big waste of money.
Chronic fatigue syndrome or Fibromyalgia (if you forgot to mention pain as a symptom, otherwise not), possibly comorbid with the possibility of IBS is my best diagnosis, alongside obvious psychiatric involvement. However you have mentioned various speisifc psychiatric diagnoses of which you should benefit from treatment (and could be the entire problem) so it makes sense to me to treat them first...empirically. Psychotherapy (CBT) and antidepressant therapy has shown to effectiveness is all of the above disorders (although with some there is contradictory evidence or only for certain sub-types) You said you were trying Tianeptine, not my first choice but give it the time it deserves - 12-14 weeks and increase the dose at week 4-6 if you haven't noticed any effects and again at week 8-10 (as a side note, Tianeptines side effects are no better than SSRI's, just different). It should also improve sleep. Duloxetine or Milnacipran is probs the best place to go next. Addition of Mirtazapine or monotherapy after the SNRI's might be best. Mirtazapine has some weak evidence for use in CFS and being a potent 5-HT3 antagonist and an antidepressant could be useful in Fibromyaliga. Pregabalin is an option for anxiety and Fibromyalgia.
You said you had a polysomnogram and nothing came up. Polysomnograms don't rule out idiopathic hypersomnia and there aren't any approved EEG biomarker diagnostic guidelines for poor sleep structure and its not considered a sleep disorder despite evidence clearly showing it having an impact on functioning.
A three month trial of rigid and strict sleep hygiene and sleep restriction has been shown to reduce microawakenings and broken sleep archutecture. The idea is to start with 5-6 hours of sleep a night and increase over about two months to 8 hours. With small changes made every day or slightly larger ones each week. Sleep hygeine should also be kept to:
- Avoid napping during the day. It can disturb the normal pattern of sleep and wakefulness.
- Avoid stimulants such as caffeine, nicotine, and alcohol too close to bedtime. While alcohol is well known to speed the onset of sleep, it disrupts sleep in the second half as the body begins to metabolize the alcohol, causing arousal.
- Exercise can promote good sleep. Vigorous exercise should be taken in the morning or late afternoon. A relaxing exercise, like yoga, can be done before bed to help initiate a restful night's sleep.
- Food can be disruptive right before sleep. Stay away from large meals close to bedtime. Also dietary changes can cause sleep problems, if someone is struggling with a sleep problem, it's not a good time to start experimenting with spicy dishes. And, remember, chocolate has caffeine.
- Ensure adequate exposure to natural light. This is particularly important for older people who may not venture outside as frequently as children and adults. Light exposure helps maintain a healthy sleep-wake cycle.
- Establish a regular relaxing bedtime routine. Try to avoid emotionally upsetting conversations and activities before trying to go to sleep. Don't dwell on, or bring your problems to bed.
- Associate your bed with sleep. It's not a good idea to use your bed to watch TV, listen to the radio, or read
- Make sure that the sleep environment is pleasant and relaxing. The bed should be comfortable, the room should not be too hot or cold, or too bright.
Bright light therapy/predawn therapy may also help with fatigue.
Idiopathic hypersomnia is much rarer and while sleep hygeine should be kept to the main treatment is psychostimulants. Due to the miriad of symptoms you are presenting with I suggest you don't use sleep hygine until everything else has been tried as it may worsen anxiety, disrupt sleep, worsen depression (although it can also improve it) etc...
You should also have a delightful battery of blood tests (some of which you have already had and some you have probs had and not mentioned/didn't realise the quack was testing you for). And for goodness sake make sure these are ordered by a doctor and not by some dodgy internet place.
I would be surprised if these hadn't been carried out and be rather annoyed at my doctor.
TFTs (thyroid function tests) to rule out hypothyroidism. I know you've had it done but it should be rechecked.
LFTs (liver function tests) to rule out chronic hepatitis
FBC (full blood count) ah hell, everyone loves FBC's, they can send you on the road to hundreds of things
BMP + Ca2+ (Basic metabolic panal/Cem-8, when including calsium) to check for kidney disease, indicators for parathyroid dsyfunction, indicator for hard to detect thyroid disorders and a shit ton of other stuff
These might not have been but are well worth having done
Hba1c and fasting glucose to check for Diabetes
B12 levels
These could be done once everything else comes back as normal.
Serology for anti-tTG antibodies for Coeliac disease
hydrogen breath test for froctose malabsorbtion
I can't see this being most of the autoimmune diease, if the problems presented that early in childhood the possible autoimmunes it could be would usually see you either dead or perfectly well by now.
There is a common saying in medicine. If you hear hoof beats assume its a horse not a zebra. Translated that means look for common diseases first, even if they have uncommon presentations. Then look for the waky 1 in a million diagnosis. Because hey, what is more likely something 1 in 10 people have, even if most have different symptoms or a disease that 1 in 100000 have? That is partly why I've taken such interest in your psychiatric problems, the rest being they are already diagnosed all just need spesific treatment and psycho-somatic diseases can cause symptoms people would never expect to be 'psychological' but it does happen.
My last peice of advice. When fatigue is the main complaint research shows that only 8.7% of people will actually be diagnosed with a definate physical disease. So don't continue expecting a magic diagnosis that you will in all likely hood never recieve. Treat any disorder you find with an evidence based treatment, don't go looking for diagnoses that aren't accepted by the medical community (ex: adrenal fatigue), don't waste your money on treatments that don't have an evidence base until you have run out the the evidence based treatments (and then always use an evidence based and theoretical approach) and keep looking for ways to live with the symptoms and improve them (including treating the symptoms (again with an evidence based or at least theoretically sound treatment (cough MODAFINIL, cough)). I'm not saying you have no hope and even without a firm diagnosis you can make life perfectly liveable. With meds start low and go slow...your cluster of symptoms suggest you will probs experience more side effects than most. Stick with a drug until the side effects become utterly intolerable and I mean intolerable or they become dangerous until it has been given a fair trial. If you can't tolerate a normal dose go lower rather than drop it. Don't try psychostimulants (including Modafinil) until you have exhuasted everything else.
As a side note, I can't see anything wrong with drinking/tablets of up to 250mg caffeine a day but make sure the last dose is at least 6 hours before bed time.
Supplements:
First of all i'd suggest against using Selegiline unless it is in antidepressive dosages (see above), as there is no evidence of benifit for fatigue and it is a 'real' drug, with some potentially big bad, nasty side effects. Also theoretically It shouldn't be that stimulating.
Sulbutiamine is my best supplement recommendation and I'm only just against you trying it before other stuff. I wouldn't even be that mad if you choose to try it alongside an antidepressant, or before one. Its basically a b vit with a fatty acid chain added to it. It has been shown to reduce anthesia (brain based fatigue) and to reduce psycho-behavioual inhibition in depressed subjects. Dosage varies from 300-2grams a day. Generally in the litriture its not associated with tolerance but some people I know have claimed to develop tolerance. I also developed some tolerance to it but it settled into a middle faze where it worked well but not like it did for the first week or so. In other words, expect a hunny moon faze but it should work afterwards as well. I would recommend starting with 200-300mg twice a day, once in the morning and once in the afternoon. Increase the dose slowly by 100-300mg/week and try not to go past 1-1.5g as I'm guessing tolerance is more likely.
DLPA, prodrug for dopamine and noradrenaline, plain and simple - it increases them and they are both exciatory. There is some very weak evidence for use in depression and pain. I recommend this over L-Tryosine because some guy once told me it can depleate the sulpher reserves and I have never been bothered to look it up. L-dopa can have significant side effects and shizzle.
N-Acetly-cestine (NAC), there is some weak evidence its useful for a range of mental disorders and its an antioxidant (what more could you want? well a lot but hey if I was going to try anything it would be )
Multivitaim - none of those super dupar uber multivits, you can have to much of a vitamin as well as to little. Just a regular, its unlikely to do any harm and might reverse any defiencies you have.
St Johns wort - make sure you aren't taking any antidepressants while on this. Obviously for use as an antidepressant but is out done by antidepressants in all but the mild severeity.
Citiocholine/CDP-choline - may stabilizes neuronal membranes, increase thyroid and corticosteroid hormones, may increase dopamine and noradrenaline and is a choline source and possibly a few other things.
