What should I do?

My boyfriend and I have been together for 1.5 years. He's done a lot of doubts wrong lately and I can't seem to get over it. About a month ago I found out that a girl tried to kiss him because I went through his phone and saw the messages of her saying she's sorry and that he didn't let her kiss him. He didn't tell me this happened so I blew up on him and almost ended the relationship. Two weeks ago he told me he was going to a party with his friend which I was ok with. He told me he was going to a party his friends wanted to take him to in a certain town. Well I can track him on find friends and found out he was actually at his former college for this party. He didn't lie about where it was because the college is in this town but said he didn't tell me it was at the college cause he knew I'd freak out. I freaked out when I checked the app and saw that he was there. What do you think I should do? I love him so much and want to spend my life with him (I'm 21 btw) and I don't know if I'm overreacting.