Leaving a 5 year relationship

I dated my boyfriend for 5 years. The relationship started a little rocky and I was young, insecure, and desperate to be in a relationship. Over time trying to keep up with pleasing him become very mentally, emotionally, and psychologically exhausting. He has always used drinking as a coping mechanism and for a while I began to use it as a coping mechanism as well. I would always go above and beyond for him playing house even though he never wanted to talk about marriage. I would check his phone a lot especially in the beginning of our relationship and would find messages with other girls. This lead me to having trust issues but I still stayed with him. It seemed like I was never truly ever able to trust him. I eventually stopped checking his phone because he told me by checking his phone that meant I was looking for a reason to leave him. It got to the point where I was building up the courage to leave him when he planned a trip to Hawaii, I went and that is where he ended up proposing to me. In my gut I knew I wasn’t happy but still said yes. I realize that was a mistake. Shortly after he proposed I heard him speaking to someone on the phone in the bathroom and became suspicious I went through his phone and found a hotel confirmation. The first check in date was for that weekend and sure enough he said he had to run some errands that day. I went to the hotel he had booked and his car was parked there. My heart dropped and called him I asked him where he was and he said he was “training a friend” who had just gotten hired at his job. I asked him if he was at a hotel and he said no. He looked out the window and saw my car came out and I asked him what he was doing he then said the same lie again. He said “we can go inside to check” once I agreed he said the truth he had gotten the hotel for a friend that was coming in from out of town he mentioned it was a female. I asked him why he had not told me he said he knew I would be mad. This is the same female I saw flirty messages with and asked him to stop talking to her in the beginning of our relationship. I left went back home packed a bag and left the engagement ring he gave me on the table. He got home realized I wasn’t there and basically said the moment I left the ring it was me breaking up with him. I didn’t respond to any of his messages until 3 days later when he texted me again. He admitted to sleeping with her and said that he slept with her because I left the ring and that was the most hurtful thing I could have done. If I hadn’t left the ring he wouldn’t have done what he did. I stayed at my parents house but he continued to message me and make me feel bad for throwing away a 5 year relationship until finally I decided to try again with him. I moved back in the lease is under both our names for the next 6 months, which also was a reason I moved back in I have so many things and no where to put them and expensive fees to break the lease and I was not in a good financial state at that moment. I feel like I didn’t get a chance to heal and I don’t trust him even less than before. For a while things got swept under the rug and went back to normal. We have recently been having problems and he wants me to admit that I think “he’s not enough for me” in reality it’s not that he’s not enough there are other factors that stop me from being happy with him. I don’t know why I can’t find the courage to leave him.