if YOU were what he NEEDS, he'd be clean now. so far you've really served as a nice "host" for items to be stolen, hocked or traded for drugs - a crash pad - food, laundry, sex - but sadly that's about ALL the need his drug addiction HAS for you. people CAN quit crack, but they really really REALLY have to want to and then go at it with everything they have - and never stop. this crack addict in your life is nowhere near that turning point......and he may never get there.
you can lock em up and they'll find a way to use anyways, or use the second they get out. you can threaten them with DEATH is they keep using, and that pipe will still be superglued to their fingers. crack really is that massively powerful (former crackhead here) and the only thing that matters is the next hit. when where and how big. everything else is just a means to an end.
he isn't that sweet boy of 22 years ago. you aren't 15. this isn't some happily ever after little romance. LIFE has changed you both. who he is now is what you must face and deal with. an addict who will rob you blind if you let him. if you collapsed on the floor, he'd walk over you to get to your purse. you love someone who disappeared long long ago.....return him to the past and move on with your own future.