How to deal with seperate under one roof

About 2 weeks ago i made the decision to end my 3 year relationship. He is an alcoholic, a pot head and mentally and emotionally abuses me. Hes manipulative, horrible with finances, and heading no where in life. About 3 weeks ago he stole money out of my purse to fund his habits. He admitted to it and i had no idea that it had even happened. It broke my heart but i warned him it was to never happen again. Ever. I will not support his habits. A few days later he approaches me and askes me for more money to buy smokes. I had quit smoking and didnt want to waste money on it anymore. I said no but also explained my reasons why. I fell asleep on the couch and unbenownst to me he stole my card and bought smokes. That was the last straw. I ended it that afternoon. Now our lease ends in febuary next year and we are stuck under the same roof as each other. He just lost his job, so hes paying for nothing. Im supporting 3 people off the pension and paying $445 a week in rent :(
He gets drunk and high as soon as he wakes up and his mood swings are f***ing intolerable!!! Hell be bouncing off the walls happy, next hell be trying to make me feel bad for breaking up with him. Im so exhausted trying to figure out what mood he will be in. Last night he came into my room and wouldnt leave. He stood in the doorway and as much as i tried to push the door shut he wouldnt budge. He kept having a go at me. I dont have a lock on my door :(
How can i deal with him whilst we are still in the same house? I don't have any money to save because since he lost his job its literally been me supporting my child and 2 adults. Im still paying off a bond loan from this house. Im fucking stuck!