Hi criticizedveggi - sorry to hear of your troubles!!! I have been on just about every SSRI and tricyclic there is, mainly because I suffer from Chronic Fatigue Syndrome and some CFS patients benefit from those drugs (I sadly did not, in terms of the CFS, but they did really help my depression, some more than others). I know that weight gain is a common side effect of some of these drugs, but fortunately I never really had that problem. I think a lot of the risk of weight gain is relative to dosage and length of time you're on the drug. Tricyclics, of which Elavil is one, promote weight gain because they can monkey with your metabolism, and Elavil os one of the most notorious in this regard. If you run a Google search on Elavil and "weight gain," you'll turn up lots of info.
I'm on so many drugs to treat all my various medical issues, and over the years I guess my general philosophy has become "if you need it, you need it" and the imporvement ot my quality of life is more important than some of the side effects, which can start to seem trivial if you're really suffering. If you need the meds for sleep disturbance, tricyclics are the way to go, but if you're really worried about weight gain, you might talk to your doc about trying something besides Elavil. I've been on Trazodone for about eight years to treat a chronic sleep disturbance, and I haven't gained a pound.
Good luck, and I sincerely hope you get to feeling better soon.