He wont leave because you're not serious about kicking him out.
You buy whatever he want or needs and allow him to stay there for free.
So why would he leave, he's got a sweet deal, with a drug fueled cherry on top.
You need to decide that he's out, he wont make that decision on his own.
Suicide?
He can die by his own hand, intentionally or not, whether he lives there or not. That's not really your problem, unless you decide it is.
I feel really sorry for your child