Sex and relationship

I don’t know how to start this but I guess I’ll just put it all out there. My boyfriend and I have been dating for a little over a year and a half and I’m currently 16 weeks pregnant. Not too long ago I found another girls nudes on his Snapchat and a bunch of porn girls that he would slid up and say yum to their stories…. I have cought him many times before jerking off in the shower which is whatever because ya know I also have a vibrator that I use when I get bored and in the mood. Going back to finding the nudes and the other stuff I still feel like shit about that and don’t really trust him but I decided to forgive him for our kid that’s on the way… well I’ve been really in the mood lately to just have sex with him and I’ve been telling him this for a week. Last night he jerked off in the shower as he knew I was already in the mood which whatever so I offered him head to rub my back tonight because my back hurts like no other and he just goes no. I asked why and he said because I don’t want it. now I just feel like shit because it feels like he doesn’t want to have sex with me and I still won’t get a back rub and if I do it will last all of 15 seconds… I don’t know what to do anymore..