We have many patients in the practice who have had to stop this medication for one reason or another. We have not encountered and ill effects from stopping cold turkey,however, we recommend starting with using every other night for a week, then every two nights for a week and then stop. There is always the possibility of rebound when you stop this medication just as any other. It sounds from your post that you have experienced some side effects which should have been addressed, weight loss, especially significant weight loss is a big deal but a frequent adverse effect.
There are other options for you and I would suggest you speak with your physician as soon as possible.
I wish you the best