I don’t know how old you are, but since you said you don’t have a car, and he live with his parents, I’m going to guess you’re both teenagers. And no judgement passed, but it sounds like you’re not really ready to be in a relationship because you’re acting out instead of communicating healthfully, and then the acting out hurts you, as well as him. This destructive behavior isn’t the way to get to a healthy, happy relationship, but it sounds like you keep repeating it. That’s why I think it might be best for you to just be single for a while…. I think that this guy probably will come back, but you’ll push each other away again.
The thing is that if he’s having a party without inviting you over, he’s not that into you. I can understand how you would feel rejected, but cheating on him because you’re being rejected, isn’t going to help. In fact, it hurt him and you! 😕 I know you said he forgave you, but it’s normal for things to be rocky after that kind of thing. Betrayal is a big deal, and it would have been wiser to just ask him why he didn’t invite you instead of cheating on him.
And if you have trust issues — it’s normal for guys to be turned off by them. Trust issues usually make people needy, insecure and they act out, like you did — to hurt someone else, as a preemptive strike. It’s a very destructive, and it would be a good idea to focus on those and see if you can work through them and understand why you have them and how to overcome them.
And finally, if you see him kissing a girl on social media, texting all day isn’t going to make you seem attractive to him. It’s going to push him away…. which is what is happening. If he’s not responding, and doesn’t want to see you… the best thing you can do is accept the rejection and move on.
I hope that helps.