Are you on any medications? I have very cynical views on "disorders" like ADD and ADHD, I think those two waste valuable time and resources. I don't know much about dissociative disorder, but I do know that different behaviors can stem from stressful environments or even things like past trauma. Now... I don't want to get into enormous detail, because I would never ask deep, inner-personal questions... But I would think the best advice I would give would be to find what stresses you, whether it be school, or your schedule, or whatever. Then find a way to alleviate that stress, and keep it out then see how you feel each day. I don't know what you've been told by doctors, or experts... And quite frankly I don't want to know. That's your information, and it doesn't belong here. It's too personal. Anyway... I would think doctors would know better than anybody, and you should always take what they say into consideration. But stress has become quite a hot button issue, and I think it would be a good thing to gain an understanding of what stresses you, and work on stress relieving techniques. It's just me talking, no MD, no licence, but it is very possible stress could hold some significance.
Edit: As far as people go, it is very counterproductive that people would rather call out and insult you, rather than understanding. I always try to be as understanding and respectful as humanly possible, and I don't see the difficulty in it. But that's the kind of society we live in: insult now, understand never.