Talk to your landlord; they can evict him.

take legal action then. simple.

Be petty, too. Next time he leaves or tell him you need something from the store. Call a locksmith or the landlord beforehand and have the locks changed and don't give him a key and don't let him in. Then pack his things and drop them outside of the door. Call the cops as well. That only works though, if he is not on the lease.

Call the cops and say he’s abusing you. Then get a restraining order.

Contact your local domestic Abuse helpline/organisation. They'll be able to talk you through how to get your abuser removed from the premises. That's what he is. This shit comes under coercive control, possibly harassment and depending on how bad he is, threatening behaviour and putting you in fear. If he's got control of/is using you for money, that's financial abuse too. There will be a domestic abuse support group who can walk you through the legal eviction steps and advocate for you with the cops. He's banking on being able to torture you until you can afford a lawyer. If you go to the right people, they'll be able to help you through the steps and be in your corner through it. Chances are, as soon as he realises you've found a way to do it, that his behaviour is being observed by outsiders and maybe even the law, it won't be 'fun' anymore and the trash will just take itself out. Quietly record enough of his behaviour and his clear, deliberate intentions to hurt you with it and go talk to the people who can help you.

If it's your apartment (under your name), and you've told him to leave and he won't, that's trespassing. Call the police.