Am I Overreacting? I want to ghost my boyfriend of 4 years.

I've never posted on Reddit so I'm unsure how to start. Forgive me, it's kinda long.

I (27F) have been dating my boyfriend, L, (28M) for 4 years. We had what I thought was a great relationship. We're best friends, and I genuinely wanted to spend the rest of my life with him. L said he shared in that sentiment. We were even supposed to go ring shopping the weekend this first spat happened.

In October of last year, I did a bad thing. I looked through his phone. He had been acting different for the months prior to this, and for any probing I made, L would say everything was great. I had that typical woman gut feeling that I couldn't shake.

Unfortunately, I was right. He was emotionally cheating on me for over a year with a woman he had been involved with previously before we got together. He prioritized spending time texting/snapchatting with her over spending time with me, was very snappy, and criticised my looks all while gushing over her. I confronted him. We started couple's counseling, and we both started individual counseling. We were well on the road to reconciliation (sleeping in the same bed, cuddling, and some kissing, but nothing beyond that).​ I thought everything was turning around. I was starting to feel secure in the relationship again.

Well, about 2 weeks ago, I got that same gut feeling. Same excuses from L. So tonight, I went through his phone, again. Fool me twice. He's been chatting and (I'm assuming based on the charges on his bank statement) video chatting women on a variety of sites: onlyfans, tangome, fanvue, telegram, even the dirtier sides of reddit (I didn't even know these sites existed besides onlyfans and certain threads on reddit like this one). Those are the sites that I know of from my quick searching. Various women, some as young as 18. He even chatted with one this afternoon when he was in the bathroom! Claimed he took so long because his stomach hurt.

Aside from obviously betraying my trust again, I got the ick from seeing these barely legal girls in his browser history. I'm hurt and numb and disgusted. I'm thinking that I just want to ghost him. Moving out and leaving the key on the kitchen counter with the screenshots I took. No conversation. No "closure." I'm just completely done with being disrespected and lied to. Am I overreacting? ​

edited to make post body easier to read