Anorexia side effect I started new medication a few weeks ago where one of the side effects is anorexia. I'm underweight already (5'6, 105lb) what can I do to maintain my weight instead of losing?

Do the right thing. When anorexia is medication induced one usually does not feel an appetite. But like many things, how you feel is different from what you know. Body weight is about a balance of calories in and out. See a dietician and get on a diet and exercise program designed to maintain a healthy weight, and stick to it, going with what you know over how you feel. Allow monitoring, and it will help.
You . You might think about calling your physician and sharing your worries about this side effect of the new medication. Maybe he will change your medication to something else without this side effect.