I think it's cool how you said you can see yourself in him. It sounds like you have a lot of empathy for him, and a genuine, true love as well!
For some reason I was just wondering about his public relationship with you, if that is a factor or not. She is his legit "girlfriend," so does that mean she gets to spend time with his family, or live with him, or share his resources, etc, while you are the girl on the side? That may be ok for you now but someday you might want a partner who you can stand beside, and who can be there for you as well.
I'm sorry for prying, I have no idea whatsoever why that came to my mind!
I don't know all your circumstances of course -- it may be that this is the perfect relationship for you for right now.
Maybe in time, he may find you to be the way cooler one, and his girlfriend's restrictions too limiting. If he is still cheating with you then I think that is possible. But I also think that he should have been strong enough to stand up to her and say he still wanted to be with you. He's setting himself up for guilt. Unless he gets a particular thrill in the sneakiness of breaking his promises to her. I feel bad for him -- wouldn't she be mad if she found out?? Not to mention hurt -- but either way, he would look like the bad guy, right?? And what about you?? You deserve better. Clearly you love this guy.
Sex is ok as long as it's without love, or love is ok as long as it's without sex.... what is this all about?! Believe me, these conversations are all over this forum, ha!
I'm not judging your man, or your situation, believe me, just writing off the top of my head! (For one thing, I've set myself up for plenty of guilt in my lifetime! Trying to avoid it as best I can, these days!) I don't like it when people make assumptions about my situation, so please don't be offended by my questions/musings, because truly, that's all they are.
Glad you are here