Oh gosh....I'm bumping this up. I have no idea about adults that don't eat. Over a year seems a bit long You shouldn't have to get someone to help you, and I think you mean assist feed. Assist feed is when you open their mouth and put a prekilled or frozen thawed mouse/rat in their mouth. They should constrict and eat it on their own.

Force feeding is a lot more harsh and yes you would want someone to help you with that. I believe you make some sort of concoction and put it in a syringe.