Steph, I'm sorry the relationship went this way, but I think it is a really good thing that you end it and at most be acquaintances (ie, no intimacy either to spell it out) if even friends. I like the choice to keep your sobriety up there and if you have to, cut your losses with the boyfriend.
At first sight I don't agree with Carol's word choice about the boyfriend. (Not sure if you do.) On the other hand, I agree with whatever it takes to be sure you are taking care of yourself, and maybe it will help to see things the same way. Being sober is the main thing, so I hope you will be OK during this change in the relationship.