Damn this sucks. I'm one of the kids that has only ever known one of my parents. (Dad left 2 months after I was born. Never saw the guy, don't really want to.)
Though, when my mom got married to another guy when I was about 9-10, he was like the coolest guy I'd ever met. I'd come to be really connected to my stepdad, even starting to call him 'dad' instead of his regular name like my brother did.
Eventually, about 3 years ago they split up for reasons I never fully came to understand. Even now I miss him, but I guess I'm just used to not having anyone there in the first place.
So yeah, I've sort of been there, it really sucks and I hope your parents can figure something out in the future.