As hard as it will be to do, you have to get the alcohol & especially the pot out of the picture.
Even people without MI are more prone to violence when they get drunk, and the pot will work directly against the psychiatric meds. I'm not anti-pot by any means, but to me it's like alcohol. Some people can drink, some people can't. Same with smoking.
Even caffeine can become a problem, and smoking makes some people metabolize some drugs too fast.
Still, it could be that he needs a dosage increase or a change.
Is the violence isolated or frequent? Do you know what triggers it?
The morning he woke you up, had he been up all night stewing about you kicking out his friends? Did they text or call him & say something that worked him up more? Does he only get violent after he drinks or smokes?
It's like a huge puzzle & you have to put all the pieces together, and still it can be hard to understand.
I'll share something with you. When my son was 18 and had his third break, we kept him at home instead of hospitalizing him. He still had insight at this time and would take anything to make the psychosis stop. During those times, we would fight over him wanting to take too much of the meds rather than not wanting to take them at all.
They tried Seroquel at first, and it didn't work, but they quickly went up to about 900 mg/day before they switched him to something else. On the last day, he took everything he could find just to try to sleep. He had a joint hidden in his room & smoked it -- we didn't know until it was too late. His dad went out to lock up the garage & our son jumped up, grabbed the biggest knife we had in the kitchen and crouched down behind the kitchen door because he was sure his dad was going out to get a gun to shoot him as soon as he opened the door to come back in.
I talked him out of the knife & we removed everything sharp out of the house including butter knives & shish-ka-bob sticks. Thankfully, they changed him to Zyprexa the next day & we saw an improvement at about 36 hours (that's when his mind still cleared quickly) - but he could easily have seriously hurt or killed his father that day.
And, he had never been violent or threatened violence before that day. He was in fear of his life and thought he was acting in self defense. I think the pot turned that paranoia switch on for him that day.
I smoked pot as a kid, and it makes me paranoid, so I get it - and I'm usually never paranoid.
My husband, on the other hand, can be paranoid just in general and pot evens him out so he's not paranoid.
It's all in how your brain chemistry works.
But, the best bet for anyone with psychosis is to just not smoke.
I know telling you to keep him off the pot & alcohol is almost as bad as telling you to look up mindful meditation, but I guarantee that if you can make it happen, it'll do way more good than anything else.