is it ok to take protein supplement?

i was diagnosed last 3 months ago, for
dibetes. And i use to be skinny, and after taking metformin and excersice regularly;
(lift weight and aerobics) my body get bigger. Is it the medicine or the excercise? My other question is, can i take
protein supplement? because this is getting serious now. I want to build a big body.
thanks please reply to this messages