My Boyfriend Wants To Kill Me With Séx - Big Girl Opens Up

My name is Chi for short, but am dating this guy from my tribe and it's not as if I really love. The thing is that he is rich, not educated but he has two businesses that are doing well. TON please dont blame me, there is no lady today who doesn't want to marry a rich man, especially if your family is broke.
The mistake I made was to move into his house and he started sleeping with me whenever he likes as if we are already married. The thing is getting too much, even when am having my "monthly visitor" he will tell me to go and watch my body that he needs séx and I don't have a choice but to do it.
He says I must get pregnant before marriage but he has slépt with me for 1year, no pregnancy...
In fact, let me just confess that this guy want to kill me. His body is big and any time he climbs on top me with all his strength I use to have body pain after everything. But I need to get pregnant.
I'm 31. I've gone to hospital and doctors say am OK! But he has refused to go for his own check. Each time I tell him to do so he will shout at me and say if I can't get pregnant I should just tell him. Am confused!
My mum knows am living in this guy's house but my dad doesn't. Pls I need good advise.
What can I do to help myself?