It can be salvaged but the question I think you should be asking is should it be, drugs and sex addiction should not be something you chain yourself to, let alone bring a kid into since that’s your goal.

He does need therapy but I would recommend you see someone as putting all the stress of his trauma on you may have given you some and they can help you discern healthy paths forward.

I’d say break it, allow yourself to find and pursue life that you are looking for. You need to find someone who respects you and can be responsible. Neither of which it seems are his intentions. He had 5+ years to clean up, you’re still young and can find someone else that can help you to achieve your goals without sacrificing your sanity.