Methadone Hydrochloride and weight gain

I have been on methadone for about 4 years. I have gained about 60 pounds within 2 yrs of being on the program. I never had a weight problem in my whole life until now. Dieting and exersize did nothing.Also have severe constipation.Ive tried about 15 diffirent drugs to help the constipation. Most of them helped the issue but still leaving me with 1 or 2 bowl movements within 8 days.If I dident take anything for it Id wind up in the er with no bowl moement at all in severe pain.Also my stomache is huge, at times I look about 5 months pregnant. If anyone has any advice for the problems I am having please let me know.

This ia my secon't time around,doing a did better.First time I became a hermit.Did not wanna do anything.Any one eles feel like that?The heat really does me in and I sweat so bad.I have craving for candy or anything that is fatning.And I never aet sweets before.I was a model.Cant speel I'm from Holland.I'm dizzy and fatiqed al the time.Concentrate forget it. wanna come down again.I'm at 75mg,how long will it take me.The first time I came down in 3 weeks I had to.For health resonse.Can anyone help me give me some tips in coming down.Thanks LULU,