I’m so confused, what’s wrong with me?

I used to like this guy because of the weird connection I felt towards him, and he like rejected me so I stopped feeling it completely and stopped talking to him. We are hanging out a lot Bc of a project now and he’s showing like a shit ton of interest and it’s driving me crazy! I hate him I swear with my heart, because I have a boyfriend I literally love with my life. I’m so confused on how I feel. And like ever since I’ve been talking to him again all I dream of is him. What’s wrong with me? It’s hard to explain really.