I need advice!!

Okay ladies I go him in 2 hours and need good advice!! A couple months ago my phone logged me out of my Facebook so I tried my boyfriends account to see if it would work. I didn’t even know his password just guessed and got it right. Since then, I’ve been logged into his Facebook but have since not told him about it but I’m not hiding it either. It just hasn’t even came up. Last night he decided to go through my phone and I think he knows about it. I’m worried because I did go through his messages Saturday and sent one of them to my friends. When I woke up this morning her last message was read but I wasn’t the one who saw it. What should I do? I’m really nervous that hes gonna be mad at me!!