Any Idea Welcomed

Hi, About 5 years ago I went on the poison called "Seroquel". The stuff has never done anything for me - except cause me to gain over 100lbs. I am down from a high dose to 25mg. So close to going off of it. I must lose weight. I am seriously concerned about my health if I stay at 250lbs. Of course, I know about diet and exercise - although exercise is pretty tough when I am in chronic pain (to the point of having difficulty walking) from carrying excess weight.

So. First off: Is there any prescription medication that assists in weight loss?

Second: Years ago, I was just a few lbs over my ideal weight. I was on an exercise program, eating very carefully, and was using ephedra (ma-huang), at that time touted as a great way to boost performance and lose weight. I felt fine, no obvious problems with ephedra. I reached my weight goal with no problem. Shortly after I stopped taking the ephedra it was pulled from health food stores because supposedly it could cause cardiac damage. It is now illegal in the U.S.

The weird part? Ephedra has exactly the same potential side effects and possible dangers as Seroquel does.

Since then, I am completely out of touch with herbal remedies for weight loss. Any suggestions?