How do I live with a mentally ill brother?

My brother returned from military school just a couple months ago. He nearly got kicked out of military school and there was literally no other option for him but to go there. My family and I had really thought that he would come home, a completely new person. But he isn't. He trashes our house, curses all the time, sticks his hands in his pants and is just plain old piggish. He takes several per-scripted medications and visits a therapist weekly. He also has a job at Safeway. But, when he is at home, I feel like he is destroying me and my family as people. I don't know what to do, and I'm not the only one in my family who notices these things (I've talked with other family members about it) Things are getting to be really terrible, and it's only a matter of time before he is supposed to leave home (he'll be a senior come ending of summer). I feel so bad, what should I do??