Well bipolar and ADHD are often mistaken for one another (
http://www.additudem...ticle/2511.html). For good reason too...they share a lot of symptoms. Schizophrenia is also often mistaken for ADHD or bipolar. Answers are difficult to find, and it's easy to get lost in the ephemeral diagnostic flux.
Typically, if you've had it since early childhood, and you never have periods of normal mood/though, it's ADHD. I say this as a general principle; it's not absolute. For example, some people have childhood-onset bipolar, and, by definition, ultradian bipolar patients experience cycles shorter than 12~24 hours. There is also cyclothymia, which is more subtle. Ultimately, the definitions are poor, healthy people exhibit some of the same symptoms as those who we label as ill, and this is a very difficult subject.
Since ADD is often co-morbid with other disorders, and can even be co-morbid with bipolar, it's important to rule out (or confirm) co-morbidity. Unipolar depression is common with ADHD,and so are anxiety, thought, personality, and developmental disorders. You're describing mood fluctuations, bouncing between optimism and pessimism. It could be temporary situations arising from life's struggles, but if there are no clear causes to your emotional swings, bipolar might be a reasonable starting guess. Unipolar depression can cause periods of negative thinking and sorrowful feelings, often followed by idealistic thinking and delighted feelings. In unipolar depression, when you manage to get control of your negative emotions, euthymia can feel so foreign and unfamiliar, that you don't know how to act, and can exhibit symptoms of mild mania or at least hypomania: excitement, ridiculous optimism, grandiose delusions, and arrogance/over-confidence. It's difficult to say for sure when a thought or feeling is pathological,and when it's normal and acceptable.
If stimulants always help you, it's likely you have ADHD. Bipolar mania tends to be worsened by stimulants, though not always. You could also have schizophrenia, since amphetamines can ameliorate the negative symptoms, but they tend to exacerbate the positive symptoms. I bring this up mainly because your dichotomy between "low" and "high" and your ideas about "vibrations", "carbs", "energy", "dreams", "intelligent infections", "hope", "hell" and "infections" are kind of "out there". You could also have generalized anxiety and just be hypochondriacal/worried about your mind.
There's too many possibilities to consider here. You can always try to relate more of your experiences to us and lurk around more, but don't expect some internet posters to work magic. If you can afford it, collect your thoughts (hard for someone with mental illness,i know) and go discuss everything on your mind with a decent psychiatrist. He (or she) studies the brain, and probably knows which medicines are worth trying for you. He might also be able to pinpoint some issues that require therapy (like a potential personality disorder or developmental disorder).