Struggling with my current relationship but seeing someone else

My boyfriend and I have been dating for almost two years. I can say that we have been fighting on and off for over a year now. There’s more fights than there is happy days. But I know that I do enjoy his presence, his emotional support, and the way he cares for me, when he’s happy. He gets aggressive and seems like he doesn’t care when he’s mad and disregards my feelings during arguments. This has been going on for the majority of our time together. There’s underlying issues regarding my trust for him because of how he went behind my back during our first year together.

Fast forward to now ~

Due to long distance because of corona, him and I have barely seen each other. This makes it easier for my feelings to fade. I offered to be Friends With Benefits with my boyfriend or to just be friends, in to which he replied “do what makes you happy”. The thing is: I know he wants me to be happy, but he just doesn’t make me happy anymore.

Upon his approval , I started having friends with benefits with another guy for almost a week now. I can say that I am guilty because I haven’t mentioned to my boyfriend about this guy, but then again, it does seem like he doesn’t care with what I do. This is THE FIRST time I went behind his back, EVER. I really want to leave the relationship but it seems hard and it gets petty at times. I don’t know what to do. This new guy seems relaxed and got his life together whereas my boyfriend just focuses on video games and doesn’t communicate his feelings for me. Any advice ?