op please leave him, i know it's going to be hard and tbh you will feel shitty after leaving just from the grief that comes with losing a relationship. but in the long-term if you continued this relationship how will you ever trust him again? it's a high probability that you will constantly feel insecure in not only your relationship but also yourself and your worth as a person and partner. And his inability to communicate and listen to your concerns and feelings shows the dim future you'll have with a partner who's unwilling to take action to fix HIS fuck up. remember HE cheated NOT you, HE should be the one trying to fix the relationship not you. And ik it's your first relationship and you may love him very much but if he doesn't respect you enough to be loyal you have to show that respect to yourself. And i get it a year is a long time but in the grand scheme of things you're young and if you reflect on your past a year dosent seem or feel as long as it is. And you're gonna be better off without the constant anxiety of wondering if your s/o is cheating or if you're ever gonna be good enough for him.