Roommate with BPD

Hello,

My roommate of a year recently told me that he has BPD. He doesn't take medication but has done extensive behavior therapy to manage the condition. We've become good friends, but there have been a few problems I don't know how to address. He often has trouble taking care of his own needs (ie groceries, chores) and ends up relying on me. Once in a while, he gets extremely angry at others, and I worry that at some point he'll lash out at the people he complains about.

Things have gotten worse these last few months: he had a bad break-up, and has been drinking/doing drugs far more than in the past. My usual strategy - conversation - hasn't worked, as he changes the subject when our talks get too personal. I want to be supportive, yet I also want a more calm/stable environment to come home to. Do you have any general tips on living with someone with BPD?