How Do You Move On?

I was with my ex for almost 3 years, things led to us having distance between us and I talked and then kissed another man..I then lied about the whole situation and refused to give a straight answer about why or what exactly happened. I was so terrified but couldn't come clean..I moved out and a few months later I was able to tell him the truth and open up. I decided to join therapy and try to work on myself and be better because I did truly love him and wanted to fix things and make it work...this March we spent a weekend together and talked...we were intimate as well. I thought that we had a chance to really work on this and I knew it would be hard and ugly, but we promised to love each other and fight through this...in June my cat got sick and I took my panic and frustration out towards him...I apologized...but he stopped talking to me for over a month...he came back and we talked for only a few days and then he disappeared again...I broke down. I started texting him from other numbers, having my friends reach out, and then even went so far as to pretend to be my friend and use her to talk to him for like a week. I ended up in the hospital for some serious health issues, and was scared I was going to die...I tried to reach out to him several more times in panic...after 7 days in the ICU, I finally got to go home...I went back to trying to reach him...which just pushed him away...at this point, I completely understand that I have absolutely lost my mind and am acting crazy...he contacted me and told me that he hated me and that he never wanted to speak to me, see me, or hear my name ever again...he told me that he had been seeing someone else and that he was done...that broke me even worse than before. Then full panic set in. I begged and pleaded. I tried to help his business. I tried to send pictures to get his attention. I tried everything, knowing that I am just digging my grave deeper and deeper...I don't blame him for hating me at this point...I don't know what I am doing or why. I can't seem to stop myself. I am terrified all the time. I am trying so hard to leave him alone and move on...yet I just keep making bad decisions in an attempt at talking to him. Help me please...someone please tell me how to be okay and leave him alone...please. I swear on my life that this is not who I want to be... (edited)