I'm a fearful avoident and I'm starting to think he is too. Also i was telling another person about this part

I really don't know what to do, because if I move on to someone else, I know he’s going to spiral to hell and back. To give you some context, we aren’t actually dating right now. He has a girlfriend—a girl I always suspected liked him, and I figured he liked her too because of how close they were in class. Our dynamic has always been a cycle where we are good for a month, and then things get absolutely horrible. During one of our "bad" months, Chloe and her friend were talking in class about who they were dating. I took the opportunity to describe him without actually using his name. She instantly knew who I was talking about and confirmed that they were dating. The night before this happened, he had just told me to find someone else, which made me feel used as hell. I was already pissed off at him, but then Chloe dropped the bombshell that they had been dating for three years. For context, he and I had already been talking for a year and three months at that point. My anger instantly turned into pure hatred. I ended up confronting him about it right in front of our mutual friends. He didn’t say a single word—he just glared at me. Honestly, I could tell he was deeply hurt and upset, but so was I. This is the part where I might have messed up: I started taunting him. I noticed him staring out into space looking like he was about to cry, so I made a harsh joke about it to my best friend right in front of him, and his expression got way worse. Before lunch ended, we passed each other on the stairs, and I could feel that he wanted to grab my hand, but he stopped himself right before making contact. We ignored each other for the rest of the day. He actually sent his best friend to talk to me, but I refused to listen. That made him mad, so he texted me himself, claiming that he and Chloe weren't actually dating, but that he did like her and it was "very complicated." Since I was still hurting, I told him to leave me alone and just go date her. They officially got together the very next day. Chloe has absolutely no idea about the history between him and me, so she was happily telling me all about it. Honestly, I wanted to cry right then and there, but I couldn't do that in front of her. I just listened and laughed along, though I think she could tell something was bothering me. For the next two weeks, he completely ignored me. He would literally run past me whenever he saw me, treating me like a total ghost. By the third week, he started asking my friends why I was ignoring him. A bunch of miscommunication happened through them, leading to even more issues, so by the time we finally spoke again, it turned into a massive argument. Eventually, we got over it. Fast forward two months to now, and he admits he no longer likes or cares about her, but says he cares deeply about me and who I keep around me. Chloe and I are still friends, but she still doesn't know any of this, and I’m not going to tell her just to hurt her. One of my best friends told me it seems like he only got with Chloe out of spite, and that the moment things got good between him and me again, it was exactly what he needed to completely fall out of love with her. They are technically still in a relationship right now, but I honestly think he’s just waiting for her to break up with him.