I would be perfectly clear with her that because of your ED you are not willing to take medication that is not weight neutral. If a medication makes another illness worse it is not helping. Worse yet if you start and stop the meds because of ED's. There are many weight options to cycle through first.

Some that come to mind is: Most SSRI's, topamax, lamictal, Abilify, Geodon, and viibryd.