Why am I still in love?

My boyfriend of 4 years cheated on me. We started living together in July and it’s only September. He “claims” the first time was in August. He had sex with another woman in his car and drove me around in it. He did all these sexual things to another woman and came back and laid next to me and did the same sexual things. He has lied to me so much. When I found out about it, it was because I found a text he sent saying he can’t stop thinking about her lips. He denied all day that it wasn’t him until he finally came clean. We talked about it alll that night and he convinced me to try to work it out. The next day he literally woke up and said you deserve better and has did a complete 180. ( He has always been this person I’m sure.) He has watched me break down in front of him , cry and cry and cry and has not shown any remorse or care enough to come and TRY to console me. He hasn’t texted me or called me. Mind you we live together. He still does things like fixed my car and we had planned a trip and he still wants to go. He still does things with me and for me. All the while texting someone else all day and being with her immediately after he gets off. He didn’t tell me the truth about the sex from the beginning I logged into his I messages and watched all his conversations and that’s how I knew. ( Before you guys say the obvious about leaving or kicking him out of the apartment he sleeps peacefully in, I’m working on it but the lease can’t be broken. It’s in both of our names and rent AND utilities would still have to be paid.) Also I have been staying at my moms house for a few days. The crazy thing is, I’m not angry at him or the girl who knew about me. I’m not mad and I actually still have love for him. I don’t want to cause him any harm and I don’t know why.

Why am I still in love after he’s lied to me and did me so dirty? How do you cope with realizing who a person really is? I’ve heard all the things in the book about focusing on myself and I am. None of that is helping.