Why am I sad, when I know I shouldn’t be

My ex and I had been together for 6 years in a long distance relationship before we broke up in February. We had been friends for 10 years before we ever got together. He was my very first relationship. I was super happy and fell in love with everything he said to me and how he was to where I would tend to stay with him for months at a time and never make any plans with my friends because he missed me a lot and wanted me to be around him. There was a time in the relationship where I would want to hang out with friends, but he didn’t want me to because he didn’t trust other people due to his first girlfriend cheating on him (I was his second). Unfortunately he didn’t even like me going over to my cousins house even though the only people there were family. The entire 6 years I had never given him a reason not to trust me and would even FaceTime him, text him, and call him to tell him about what I was planning on doing or what I did for the day. Even though I know it’s my fault for not standing up for myself and making my own decisions, I continued to let him choose what I could and couldn’t do, but that’s because I felt that’s what love was and that it was a compromise. Throughout our relationship, he wanted to break up with me multiple times but never went through with it because he felt bad when I’d start crying or because he thought I could really change for him. I’ll admit that I wasn’t a perfect girlfriend and I had moments where I got mad at little things when I shouldn’t have. I should also mention that during this time I had found that he had other girls still messaging him and he would try to lie to me and say no one messaged him even though I could see it in plain sight because we were on his phone together. In 2017, we decided we could move in together because we loved each other and wanted to start a new life together while I went to school. After 1 month of living together, he decided he didn’t love me anymore and didn’t want anything to do with me, one of his reasons was because he didn’t like the way I looked anymore. We still lived together and were codependent on each other for the most part. After our lease was up he moved back home 3 states away. We continued to talk, but were still not considered in a relationship. 6 months later he was still confused about his feelings and decided to give it another go. The same cycle of him telling me who I can hang out with and where I could be continued because I really just wanted to be with him because I loved him and felt that I should be able to do anything because I wanted him to still love me back. Fast forward to 2020 and I realized that by this point he should be able to trust me. I finally put my foot down and said that I was tired of feeling like I had no one else to hang out with because I had pretty much became a terrible friend and abandoned all of my friends for him. So I told him I wanted to start working on myself and feeling like myself again. I had gotten into a new type of music genre that helped me gain some confidence to make me feel this way and he was very disapproving and would always get angry whenever I would bring it up. However, I started working out so I could be happy with myself and be healthy. He was not happy about this because he didn’t like that where I worked out had men and even when I worked out at home he didn’t like it because he said it would take away our time even though I called him after every work out. I eventually reached out to friends who reluctantly forgave me for being a terrible friend and abandoning them. He disapproved of all of them except for 1 (all of my friends I reached out to and hung out with we’re only girls because I still felt that it would’ve been disrespectful if I wanted to hang out with men). Over time I started to see how I was being treated in a way that I didn’t like, esp when he would get angry with me if I couldn’t answer a text whenever I’m with someone or family. This is because I don’t like to be on my phone whenever I’m hanging out with friends and family because I genuinely want to enjoy my time (but I do see how I could be in the wrong here). I would try to communicate with him about things I didn’t like and would reject what I say and said that he doesn’t act like anything I’ve said and would tell me things like “I put up with you way more than anyone else ever could” “if you were with any other guy, they couldn’t treat you how I do” “I know how guys work, i wouldn’t do that to you” etc. eventually this made me start pulling away slowly and eventually we broke up 6 months ago, but still continued to talk because I was more than happy to stay friends since that’s how we were before. 2 weeks ago, he completely stopped talking to me and removed me off of Snapchat. And a few days ago he decided to call me because he felt that I had a right to know that he was seeing someone else. That someone else was his ex who had cheated on him and was his reasoning as to why he did what he did. He had always told me that he would never go back to her or even give her the time of day because of what she did. When he told me this I felt extremely hurt. He then went on to say all the ways she’s better than me. This is what really got me and it’s been really weighing on me to where I haven’t eaten at all in a few days and haven’t had a lot of sleep. Those words really hurt me and has made me feel like I was a crappy person in the relationship and that this would keep me from ever being in another relationship because I truly don’t think I could be a good enough person for someone else. My family and friends did not like him at all and were super happy for me when we called it quits. This makes me feel like I really shouldn’t be upset over this, especially when everyone tells me that he wasn’t good for me due to the way he continuously treated me. I will say that he did have some qualities of someone that I could ask for over and over. He also asked me to do something for him that I believe would be considered cheating and even he should consider as cheating, but I haven’t because I just wouldn’t feel right about it. I’m just completely torn over this situation because I believe that I really shouldn’t be sad, but I can’t help it and haven’t talked to him since.