How do I live with myself after this

My ex and I were together for 3 1/2 years and broke up recently in June. Directly after the breakup, things were confusing, and we both still had hope for us. However, what led up to the breakup was completely my fault. I started becoming very jealous of past events that didn't even matter in our relationship at that point. Whenever she was at work and people would hit on her, I would get extremely mad at her even though it wasn't her fault of course. I hate myself for getting so angry and letting little things like that completely ruin us and her. I would send her awful texts with things I could never take back. I would constantly threaten to breakup with her and say that she didn't care about making me happy, even though that's all she wanted. I don't know how to move on from this when everything was my fault. I verbally abused her for about a year until the end of our relationship. She was everything to me, I genuinely don't care about anything else right now. Us being together felt like a dream we would mostly just sleep, eat, watch, drive, and spend all our time together. Before we got together we were friends for years but we would constantly get into fights and have periods where we wouldn't talk to each other. I don't have any friends and no one to talk to about this. I really think I've learned and I would never do anything like that to her again. I have no idea how to move on from this and I have no idea how to not hate myself for ruining the best and only relationship I had in my life. Please help me I will take any advice.