If I were you, I'd have an mri because some of these psych meds (risperidone I'm looking at you) can sometimes cause small "benign" brain tumors. Just recently there was a girl in the news who had brain surgery where something went wrong I think with her pituitary gland. Now she can't stop eating and became obese practically overnight. Unlikely and not meant to scare you, but something to consider.

I'm a 6 foot 190 pound man and I can comfortably get by on less than a 1000 calories for a day or two if I must. My only other advice is to drop every addicting substance you consume. I don't eat pasta, sugar that isn't from fruit, grains (other than a very specific bread on occasion), processed,/fast food, and I only drink water most days. After making that change my energy and sleep is better, my emotions are less volatile, while exercise was the only thing that leveled out my mood and stress.