I feel your pain... in the past I have taken Seroquel and been fine, because I was also taking Wellbutrin (which is an appetite suppressant). But my doctor just took me off Wellbutrin and doubled my dosage of Seroquel... boom. I gained 10 pounds in two weeks and it doesn't seem like it will stop any time soon, as my appetite is still insatiable.
I have told my doctor about my concerns with weight gain side effects because I also am in a very rocky recovery from an eating disorder. He said he just wants to try it. I see him again in two weeks and hope that he will be open to trying something else.