Firstly, I don't think it is so much of a question of "how much" NE, but more of where it is. You could have overactive NE in the striatum, but low activity elsewhere.
We share a LOT in common. I am the same way, the dullness, especially the conversational problems. My BP decreases on stimulants, and my heart rate stays about the same (depending on the stimulant)
How do you respond to ephedrine or the combination of pseudoephedrine and piracetam? That would be a good place to start. They are paradoxically both calming and stimulating to me.
For me, amphetamine does not fix all of this. It helps somewhat with conversation (helps generate words, but I still have the 'static'/dullness feeling in conversations). It really helps with concentration and overall dullness, and I feel like a more "cured" version of myself, very natural.
Methylphenidate fixes most of it but produces a slightly robotic feeling. I don't dislike the feeling, but I think it could possibly be damaging to your social life or personality (for me, it makes me SUPER calm and EXTREMELY nice and lovey-dovey to everyone, but very, very boring. Maybe you know people who act like that normally.) It helps more with the static/dullness. It is very easy to have a conversation on it... but that conversation could end up being me saying "yeah" a few times and smiling at the person for ten minutes, and I would feel like it was a great conversation (and I would be clear-headed and focused the entire time) while it actually probably isn't a very good conversation to them.
Ritalin also makes a big distinction between my "social anxiety" and the social problems that we share. The social anxiety (speaking in front of a crowd, confronting authority) is a bit higher with ritalin (I kinda had a panic attack during a presentation while on ritalin) while the other social symptoms are virtually eliminated. Amphetamine does not seem to increase anxiety as much.
What works well for me so far, and keep in mind, I am not recommending this due to potential for bad tolerance, is amphetamine (vyvanse) combined with chronic 1g phenibut (and some other noots/racetams, see my profile). I am still waiting to see if tolerance will build to the social effects of phenibut (reduction of the static). If it does, I plan to taper down and forget about it. But with this combination, presently, I am probably at the height of my functioning. I would say I am completely rid of mental "disorders" I have, and striving only toward nootropic improvement and other aspects of my life I wish to improve upon. But otherwise, I feel, as a rare occasion, completely free from cognition disorders. If you want, I can let you know how it goes, if I build tolerance. It is too early to tell right now, but I don't appear to be building any tolerance. Still, don't take this as me promoting phenibut as a wonder-drug. The addiction to it can be horrifying, and there is a high chance that I will develop tolerance, but I am going to wait it out and see.
You also my want to try stablon. It has a very nice pro-social and pro-concentration effect for me, but I have never used it for more than a day or two in a row, so I can't say if that is just the initial stimulant effect or the actual long-term effect.
Another thing, if you are chronically stressed by life situations (like not being able to concentrate on anything and thus having to work 10x harder and work CONSTANTLY/constantly have it on your mind to get anything done), then it seems to make everything else much worse, the anxiety, physical sensitivity, etc.
Reducing that stress will improve life by a lot IME.
he said I clearly don't have ADD because I had a good attention span as a child
Define attention span as a child. Many children can go through school and everything very easily. School is easy, and you could easily look like you are paying attention when you really aren't. Childeren with ADHD can also often concentrate easily on things they are interested in or on things that don't require much mental effort (especially important if you were gifted). The problem with attention span appears when attention must be sustained on either a repetitive or mentally effortful task.
For example, if you had mild interest in math as a child, you probably could concentrate fine on it when learning new concepts. They were easy, and the effort to sustain the attention was very, very low in comparison to the reward gained from understanding.
However, you may have had a difficult time with sustaining attention on things like memorizing multiplication tables or doing homework.
and made excellent grades all the way through high school
Nope. "Giftedness" does not counter an ADHD diagnosis. Above average intelligence, memory, or even just very strict parents (anxiety can motivate GREATLY) can cause great grades all the way through highschool. Especially if you are inattentive type where there is no oppositional defiance (in many cases even more compliant with authority than normal).
I would suggest finding a psychiatrist who sees a lot of ADHD patients of all varieties. They will be able to assess it much better.
As a final disclaimer, I may be a bit too enthusiastic about the combination I am currently on, so keep that in mind.