Stress after family member (and family) moved in

I live with my parents currently, as much as I really don't want to.  I wish I lived alone, like I did in the past.  I am in my forties, pretty much alone, depressed, stressed and generally not in a brilliant place.

My brother and his family moved in and his wife had a second kid.  He keeps moving things in the house and throwing things away and the stress he is causing me is really high.  I started chomping down 1mg of Diazepam twice a day.  I can take a lot more than that, but up until now have never had any real need to use it at 6mg a day.  Everytime I go downstairs, he's moved something, changed something, put something new in the house.  I am getting more and more stressed by the day.  It will come to a head at some point.  Last time that happened I knocked his head off and gave him a pummelling many years back.  He didn't talk to me for a year, but I wasn't particularly bothered.  It would be better if he moved out before it reaches that point.  Or maybe I should, but accessing social housing is a long process.  I am not in a position financially to just move out.  I wish I was, I would leave in a heartbeat.  I do have a van with a bed in it, though.

Right now my life is in transition.  I have another year of college to complete.  Once that's done I will no longer be tied to this place and can go and disappear and leave all this chaos.  I have my own hopes and dreams to follow, but I need to sort out my education first, then make some money.  With money comes the ability to enact projects.

I love my brother, don't get me wrong, but I also really hate him.  I won't elaborate beyond that.  Vitriol is at the highest point, probably ever.  I am spending increasing amounts of time trying to work out how to get him to leave.  Obviously nothing can be done overtly or it will cause blowback.  I wish he had never come back to this country.  Life was much simpler and easier back then.