I think you're just upset at the fact the only friends you have picked him over you.
Just because he does have other people he could live with, doesn't mean he should have to just so you have somewhere to live.
It's a rubbish situation to be in, and yeah, I can see why you're upset, but you don't have a right to those 4 people, you don't get to decide that you're living with them, so he needs to find somewhere else. Honestly I'd just suggest you either put up with him, or resign yourself to living at home.
You said you were in societies, how have you not got other friends through those?