Should I Go Back To My Ex-boyfriend Who Cheated On Me?

I found out he was cheating on me with some girl. I couldn’t trust him anymore and I felt heartbroken/betrayed, so I broke up with him. Ever since then, he’s been trying to win me back by bringing me flowers, chocolates, and constantly calling me on the phone and showing up on my front door. He said that he’s in love with me and that he regretted cheating on me, that it was a mistake. He just kept insulting himself for what he did, and he said that I was all he ever needed. I just shook my head and didn’t know what to do. I’m still in love with him, but I could never trust him again.
Then one night, he came into my house by using the living room window. I told him to get out, but he kept convincing me to take him back. It was raining outside, so he was all wet and his eyes were red from crying. He literally begged me to be with him. But I said no. Then he went in my kitchen and took out a knife. He wanted to prove his love to me, so he cut himself on his arm and blood started coming out. I screamed and panicked and I told him he was stupid. I took the knife away from him while he was sobbing and repeating “I love you”. I took him to the hospital, left him there with a doctor and went home.
I don’t know what to do. I love him very much and we dated for a little over a year. I trusted him completely, but then he betrayed me. What should I do?