I’m having a dilemma 😣 to break up or not? LONG POST

I have a boyfriend of 2 1/2 years, a few months ago I found out that he cheated on me during the summer. I told myself a million times that it’s nothing and it just happened last summer and there’s nothing I can do about it, and the length of time we’ve been together stopped me from breaking up with him for good. When I confronted him about him cheating, he also said that he does text other girls while he’s drunk and sometimes slides up on their pictures. But, he claims it hasn’t gone anywhere. I took him back and told him he needs to start showing me that he loves me and stuff and he needs to hold me tight. He said he will do whatever it takes. Recently he has been drinking a lot and taking his anger out on me. We argue every time we drink together, because he just can’t handle himself. When we hangout he doesn’t even really “hang out” with me. He plays a game in his phone or watches YouTube videos. When I pick HIM up, he does the same thing. I always ask to go on dates or do this or do that. He never asks to do anything. I told him before I feel like I’m the only one putting in the effort and I don’t see it for him. He got defensive and made me feel bad. Just this Sunday, was his birthday. I was pretty busy as I was in my school musical and over the weekend was our show. After our Sunday show I went to grab a bite to eat with my brother and my boyfriend got upset with me because I went to eat instead of going to his house to see him in his birthday. I stopped by there after I ate and hung out there, but when I got to his house he was drunk and crying and blamed me for everything and wasn’t even appreciative that I was there. We got into an argument and he told me to leave, so I did.

My brother has a good friend that he grew up with, he is 21 years old. He’s been hanging around at my house with my brother, and I’ve been close with him too because I also grew up with him. He always jokes around with my brother that he’s going to marry me someday. Well, my brothers friend and I had a talk about my relationship because he saw that I was upset so he told me to let it all out. He listened.

The way he talks to my brother about what he wants in a girl and stuff, he describes me but doesn’t know it. I finally told him everything I want in a relationship and he told me I’m the perfect female. He is the kind of guy that wants to go out al the time and do fun things together. He will watch any kind of movie, he will do whatever his gf wants to do. He’s a gentleman. I’m only 18 and he’s 21, but it doesn’t even feel like he’s older than me.

My brother wants me to marry his friend and his friend really wants to marry me. I kinda have a thing for the guy, but I’m in a relationship and I’m starting to see it’s not as healthy as it used to be. I have no idea what to do 😣 can someone please give me advice??