Help ladies I'm desperate!!!

Okay ladies so Me and my bf been together for 5 years and our sex life is a big issue when the sex is good it's great BUT when it's not satisfying as it use to be he will finger me kiss me ect. But I rather get myself off tbh and he watches porn (so do i but I dont hide it from him ) he hides porn from me he jacks off in the other room knowing he can fuck me I honestly have a feeling hes more into porn and online chatting with other girls then to be with me (yes we both cheated yes we trust each other).. but for some reason I know in my gut something is off and I've been feeling like this for a while can somebody please talk to me before I actually leave him its gotten to that point where I wanna cheat so bad but I love him so much .....