What do I do

Some backstory first: I have had this thing with a guy for 3 months were both 18 (seniors in high school) were practically dating without the label and have made it clear with each other that it's exclusive.

A month and a half in he made out with a girl at a party and it was a struggle but I decided to forgive him and genuinely thought I've been over it BUT

Over the weekend after I had drank a lot at a party I got sad and drunk texted him about how I really liked him which was scary but I didn't trust him which was more scary and how I was afraid he would cheat on me again

I just like him so much but what if I can't get over it? Im just confused now bc I thought I was over it and now I don't know what to do. It doesn't help that we're not "boyfriend and girlfriend" I think the label would help but idk