How can I deal with my alcoholic housemate?

My housemate is an alcoholic. He told me after we first moved in in October, he was fine for the first few months and he didn’t touch a drop of alcohol. I have had trouble with him not paying the bills in the past, taking my food but recently he has been taking my alcohol and going on long drinking binges, this last one has been going on for over a week. He got arrested 10 days ago for smashing up a police van and has court next week for it.
I am in a house contract and can not move out without having find someone to replace my contract. I have had to front the money for the bills again this month and the house is a mess, I have tried to clean it up but he keeps spilling beer etc everywhere and drawing on the walls(!) I am trying to get on with my masters thesis (as he should be). I cant move out as I would worry about him and can not afford to pay double rent until I find someone to replace my contract however, I cant afford to mess up my masters and continue to pay for his share of the bills either (although this is the cheaper option).
I have moved all of my alcohol out of the house and now keep it at my boyfriends house but he still prioritises buying alcohol or pot over anything else. He is a great guy when sober and good fun. He can drink in moderation and when he does he is a good mate on a night out however recently he has just been trying to start fights and a few days ago woke up in the middle of the pavement in the town centre not knowing how he got there.
I am getting down worrying about him.