I obviously don't mean like flip out crazy (although that's what I feel like doing right now lol)

I finally, after 2 years looked through my bfs phone real quick while he was in the shower and found out he was snapping another girl. It was 7 months ago but... He's been acting weird these past 6 (or should I say 7 lol) months and has been non-stop accusing me of cheating when I literally never leave the house and the only people I talk to are him and my mom. Never been unfaithful or even talked to anyone else or thought about it! Since day 1 I've been devoted. But back to the question, would you bring it up/flip out or just let it go because it's been so long. Help, idk what to do I feel so betrayed and also like dude you've been accusing me and you're the one stepping out like wtf!!!