I feel completely alone right now. I love my boyfriend deeply, but, recently, I found him texting another girl after a night out. He’s cheated before, but, foolishly, I forgave him. He says he’s sorry, but, I just don’t know what to do at this point. I don’t understand what I did wrong for him to cheat on me. And now every time that he leaves to a friend’s or his cousin’s house, and I think he’s cheating. I’m completely lost on what I should do.
LemonVibe 
RUN! ;P
You deserve better.
^ See that statement? Now keep repeating it until you understand that it’s true. Leave and don’t look back.
Leave him. You will feel sad but the weight of worrying will be lifted from your shoulders. You are responsible for your happiness and this guy, as much as you may care for him, is holding you back from reaching your happiness potential.
You definitely gotta end it. Easier said than done but you are not happy. You’re miserable in this relationship. It’s unhealthy to be feeling this way and having negative thoughts weigh you down when you’re not with him. First person you need to take care of in this world is yourself so my suggestion is to do that.