Roommate Owes Me Money

So long story short I helped my friend out of a really shitty situation he was in supposedly from his last roomates screwing him over. He is now doing THE EXACT SAME THING he claimed they were doing. I have to treat him like a teen and get him to clean up after himself to not damage the property we are renting. And he litterally smells all the time and i have to turn off my homes internet to get him to do anything. Anyway that's beside the point.

I lent him 2k to help get him out of his lease where he was and move into a place with me. The first 6 months of the lease he was working and slowly paying down some of the dept to 1.2k and was paying his portion of rent and a coupke bills. He lost his job 3 months ago now and has racked up a dept with me of 5.6k from rent, utilities, groceries, and including the original dept. I want to make sure he is still obligated to pay me after the lease is up in 6 months including any additional dept he gets with me through the remainder of the lease.

I am an assistant at a law firm so I can ask my boss to write me up something bit I want to have a better idea of exactly what I need written up so I dont approach him not knowing what I need.