Honestly I would talk to your pdoc about your meds. Prozac reacted that way with me & I lost so much weight that I landed in the medical hospital. Like you, I got started loosing because it wasn't a problem & I always wanted to get thinner but just never bothered until the meds made it so I didn't even feel like eating so I didn't. First thing my pdoc got me into an ED treatment center....only problem they really didn't address the REAL problem & with the meds I was on I still hated the taste of food & felt sick every time I ate.
LOL...after I got out of the treatment center he changed my meds to Welbutrin which reacted the same exact way for me so that didn't do any good either. I went on like that for several years though I was finally able to get stable on at a very low weight.....it was difficult to not want to keep loosing. There is something very addicting about seeing one's weight drop though my logic said....there is no way you can weigh nothing & still be living.....but at that same time, I really didn't want to live anyway so anorexia was also sort of a passive suicide attempt anyway after all the other attempts hadn't worked.
The most important thing is making sure your pdoc knows what your meds are doing to you & he needs to know that your reaction to them makes it impossible for you to "just eat" because of the nausea that it's also causing when it comes to food.
Yes, this can cause you to get very ill with anorexia. It's NOT always about body image even though the ED treatment centers want to think so. I have never heard of an ED that doesn't have some other very serious issues behind them that are triggers & they aren't just wanting to get thin or seeing one's self as being fat.....there are many serious emotional stressors including abuse that people have gone through along with meds that are the start of the weight loss & it just goes downhill from there because weight loss does seem to be so addicting when seeing the scales going down.
Don't allow it to get started & don't allow your pdoc to talk you into meds not being the problem. It's not something you can stop easily on your own & it's important that your pdoc knows & understands the problem.