Opinions...what should I do?

My boyfriend and I have been together for 4 almost 5 months. The first 2 months we always used condoms then when we were 3 months in we started having unprotected sex because I got on birth control. Then shortly after that I started having problems and I found out I had chlamidya. He didn’t have symptoms so he didn’t know and he said he didn’t cheat so I believed him. But me and my boyfriend met on a app so out of curiosity I decided to make a fake account. And I found he was still on it and his activity showed he was on it 5 days ago. I confronted him and he said I wasn’t talking to anyone I forgot I had the app and never thought to delete it. He showed me screenshots that he didn’t open up any chats on it and blah blah blah. So I let it go I just said just delete it today he said he did. So then 2 days later I checked again and he was in it 15 mins ago. I was so mad because if his reason was oh I forgot it was on my phone and that he accidentally clicked on a notification. Now it’s he still had it after he said he deleted it. He wants to say I don’t love him or I don’t have trust in him. But he gives me a 100 and plus reasons to no to. I really do love him and now I feel guilty. I broke up with him 2 days ago but now I’m acting I want him back. He’s being dramatic like i need time you broke my heart. But what about me and the trama I been through these past couple months. I’m 18 and he’s 24 he’s my first everything. So I just go or try again with him? Is it cheating if he had the app on his phone but “didn’t talk to girls”? I’m I dumb to stay with someone who gave me a sti should have then been the reason for me to leave? Man I just don’t know what to do...