Can’t stop fantasizing about someone else

I try so hard to let it go. I just can’t stop thinking about this man. I feel like I SHOULD feel awful because I’m in a relationship. But I don’t smh. I feel trapped. I told my boyfriend about these feelings and that I never set anything up to meet with the other guy because I don’t have it in me to cross that line but it’s been about 2 months of me feeling this way. Not to mention before I got in contact with this other man, my bf and I were slowly disconnecting anyway. It’s been 2 1/2 years and I’m honestly tired. We’ve only spent maybe 8 months of the relationship together. The rest had been long distance and I stayed loyal to him thru all the loneliness, heartbreak (he was texting multiple girls and I found out on our fourth month of dating). I just don’t wanna be in a relationship anymore. I feel trapped. That’s a whole other issue that he said we can go to counseling for when he gets home but I don’t want to tbh. I don’t care anymore. And now I have these urges to be with this other guy physically (no emotional piece. I don’t wanna be with anyone on that level right now). I feel like such a....guy 🤦🏾‍♀️ I feel selfish, I feel emotionally unavailable, and I cannot understand why I don’t feel guilty. I need some advice that isn’t preachy. Before you respond please make sure you remember that you aren’t perfect either. Thank you.