You sound younger than me, so I'm going to clue you in on a secret to life.
> no financial situation to move anywhere else
That doesn't exist. You make decisions first and then figure out how to execute/pay for them later. We're not talking about buying an island here, we're talking about having a really base level of happiness with your entire living situation.
Move out and get your own place. Figure it out, you're smart.
If you're not up to the challenge, then just tell him you'll kill him in his sleep if he does that shit again.