Feeling lost and alone...

I don't want to bring anyone's mood down but I just need to vent... I'm 33 weeks and 2 days pregnant with my fifth baby. I'm not working and barely getting by, but my boyfriend works (sometimes). He helps sometimes, I pay the bills... And I stay home with the kids... He does fix my car which has been acting up. Anyway, through out this whole pregnancy he's always acusing me of cheating on him. He use to help with the kids more, even just so I could go to the store without kids. But now if I want him to stay with the kids so I can go anywhere by myself, to him it means I want to go meet up with someone. To makes it worst I haven't wanted to have sex most of this pregnancy and I find it hard to have an orgasm... I feel I have NOT done anything to give him a reason to think I'm cheating... I'm not cheating... I've been a lil depressed... I'm always home by myself until my boyfriend wants to come and send time with his family. Which could be 10pm or 2am, but I'm the one cheating??? I don't feel any support from him in life or with this pregnancy. I try to let go but, it so hard when you've been with someone for almost 9 yrs.