Am I overreacting if i want to break with My boyfriend because he lied to me, made think I was insane of even thinking of that online to find out he was lying to me?

I (18F) have been dating my boyfriend (18M) for almost two years now. He is sweet, and we've had issues but we do work through them. He respects my boundaries so what happened was completely unlike him.

Last night something had happened to him and he had told me about it and told me how he apparently found a reddit post talking about the same incident that happened to him in the same time frame and such. I immediately noticed something fishy when I asked him to send me that post because he was telling me that he couldn't find it. I ended up searching up for it and the whole post was written in his exact way of texting n stuff. So I was jokingly asking if this was him. He said no, but his tone was weird (this happened over call). Then I was checking through the account and found another post in another subreddit where the account was detailing their hair care routine asking for advice on their hair routine. It was his exact same hair routine. Then I found a comment on a hookup subreddit that was quite recent. I obviously confronted him about it and he told me it wasnt him. I didn't believe him at all and I was acting kinda crazy telling him that I dont believe him, and stuff along that, but he did gaslight me and was telling me i wasn't thinking straight and borderline (or honestly imo was) implying that i was insane to bring it up. I initially believed him and he was talking about how he had a panic attack and all that stuff and was very mad at me. Which is fine i guess until that point.

Today morning we spoke and I asked him to reassure me about last night. He half heartedly did but then got triggered that I brought it up.

I know this is controversial, and never in my life, even in my previous relationships I have not done this but I hope yall understand how uneasy and restless I was feeling. Fast forward to today evening, I had a really strong gut feeling and I asked for his Gmail account to see if I can log into the account. He told me I was mental and I was being insane and that this would ruin our relationship. He was so insistent until eventually he did give it to me. I log in to reddit, and its a new account. I obviously thought it was fishy because it was made today. I checked his spam folder on Gmail and found the account he was telling wasn't his. The reddit account is relatively normal but he's in that subreddit and another weird one.

He finally admitted the account was his. I was really hurt and upset. He was apologizing profusely but idk.

He told me that he commented on the hookup post to troll the person but idk. I was checking his search history too and it shows he did search for a hookup site. He says its because "he wanted to message people to troll them". He told me he didn't want to admit the account was his because he was afraid I would think he was a creep. But I'm more upset he disregarded my feelings last night and called me crazy for thinking this, when all along it was true and he was hiding this from me.

I know he does this trolling thing but I wish he was honest with me and told me.

Now I dont know if things can be okay between us. I'm so hurt and upset because he has been almost perfect boyfriend. But I know this is out of bounds. So should I break up with him?

TL;DR

My boyfriend lied to me and made me think I was in the wrong for confronting him about it, only to find out he was lying and now I'm unsure what to do