AIO i went thru my (ex) boyfriends phone and caught him cheating on me and then he turns it on me

hi all!! this just happened to me like a little less than 48 hours ago. i (23F) have been seeing this man (21M) for almost 7 months and been official for nearly 3 of those. i met him at the restaurant we worked at. he had been acting real off recently so i decided to go thru his phone bc i had a sense he was cheating on me. there i found about a dozen DMs to women asking for their snaps on instagram, and maybe about 7 girls on his snapchat that he was saying inappropriate things to - one of which i opened. i also found his NSFW reddit and instagram pages (not mentioned). i opened one of the snapchat’s from the most recent girl and then reached out to her on instagram. i would like to clarify that i have not once been unfaithful to him since we made our relationship exclusive. he accuses me of talking to minors, one of which was a boy (18/19) that we both worked with that i genuinely viewed as a little brother. i know he is just projecting his insecurities on me because HE TALKS TO MINORS. 2 17 year old hostesses at our job informed me that he was trying to pick them up while he was 20 at the time and i never told him i knew that. as you can tell i really ream into him here and this was all a couple hours after i went thru his phone and woke him up screaming at him. i feel like im kinda justified bc he is clearly trying to manipulate me here, but i do think i could have handled this a better way and maybe just not said anything at all and cut off all contact.