Not sure where to turn from here

My boyfriend and I have been trying to have a baby about 8 months now but nothing. He has no kids at 40 and i have four from my first marriage. I wanted to give him a baby but now he just complain and wine about everything i do.. Im not saying that his winning is completely unmerited but when i try to tell him my part of how he makes me its like im supposed to just except it and my feelings don't matter. He withholds sex like its punishment so getting pregnant now is very difficult anyway but At this point im scared to get pregnant. Can anyone offer some advice?