I cheated on my boyfriend while drunk?

Me and my boyfriend have been dating for 1 year and a half, which is a very long time for our age. I know I was so in love with him and he said he loved me too. He was my first. In the beginning of our relationship, I kissed another guy in one of those stupid kissing games like spin the bottle. It didn't mean anything but he almost broke up with me and it hurt him. I swore to myself id never ever cheat again, I apologized all the time and told him id never ever do it again. I don't want anyone else. Then, a couple nights ago I was at a party. I don't have much experience with drinking, i'd only been tipsy before. Someone brought out some tequila and before I knew it I had way too much. I fell down the stairs and passed out. I was out of control. Then, I started making out with this guy that was my friend. I had no feelings for him. I hardly remember it. I couldn't think. Turns out that guy was completely sober and took advantage of me. He knew I had a boyfriend. That morning, I felt terrible. I couldn't keep that huge secret from my boyfriend, so I told him. He is in Michigan for the summer so I couldn't even tell him in person. He was heartbroken. He told me that he had to take a break, he couldn't get hurt again. I didn't want to hurt him again. I told him I was sorry a million times, everything. even after he told me he needed a break he said "I miss you," and "I love you," He also said he wanted to continue talking and he wanted me to be his best friend and just be there for him. I agreed. He said he owed it to his friends, who had been warning him that if it happened once, it could happen again. I don't know what to do! It hurts so much. He also says he's sure we'll get together again someday and that he wants to see me when he's back. He also said he's not seeing other girls, and i'm not seeing other guys. I hate myself for hurting him. What should I do? I can't stand this empty feeling.