Hi Jay
Sorry you are dealing with this right now.
Can you ask him if he has anywhere else he could stay? If he can’t abide by rules then he can’t stay in the house. Point out that he is putting others at risk and if it continues he needs to leave.
As far as the drugs, only he can get help. If it ultimately leads to homelessness then that is a direct result of his actions and he has to deal with that. You are enabling him.
It’s hard but you have to stop protecting him from himself.
I’m in your position but further down the line. My addict is in recovery and I had to do what I’m advising you. Step back and stop covering. It will get easier for you xx