You've only been on it four months so now is a great time to change your diet and watch those carbs. I find if you nip the weight gain in the bud early you can learn to manage it quite well. As for going off them so soon I would advise against. I don't have schizophrenia but suffer with psychotic symptoms and was told I would only be on medication short term which is considered to be about 2 years, maybe more.