It sounds very likely that you do suffer from the condition, but self-diagnosis is never a certain thing. I diagnosed myself with Ulcerative Colitis and it turned out that I did in fact suffer from the condition, but you need an expert opinion to confirm.
All of the symptoms you listed are also consistent with hyperthyroidism also, weight gain can occur in both conditions. I'm guessing you have a genetic predisposition towards hyperthyroidism, so I wouldn't rule that out either.
I hope you sort things out soon and keep your symptoms under control.