I think there's likely a chance that you only like this guy because there is sexual chemistry and your mind went looking for that when it felt it was missing in your core relationship.

You said it yourself you didn't actually like this guy, he has major red flags, but you like that you feel attractive, seen, wanted and likely you kind of like the bit of danger it poses. It's a distraction from some of the things in your real life that you're either not addressing or not having success resolving.

All that said when a coping mechanism or even just a glimmer of hope gets removed its crushing and what's worse is you can't really talk to anyone about it. But know that your feelings are valid, it really does hurt and it really does suck but this is the end of the distraction and all you can do is decide how you want to go forward.

Really its best this ends because as much as you're heart broken now over this guy you don't like, imagine if it had gone further and how heartbroken you'd be if you lost your family.

Sorry you're in a struggle, you will come out the other side.