SO is now second guessing kids

Opinions! My SO and I planned on starting our family this fall. Over the last few weeks he has been acting really strange. Finally was able to talk to him and he says he's been having second thoughts. He says he is not ready. He is scared to be a parent and doesn't want to be anything like his parents growing up. His family is so broken and it is sad to see how much it has effected him. I'm afraid the longer we wait the more he will decide he doesn't want kids. He is worried he is going to mess it up. I've told him it's good he is self conscious of what he doesn't want to be like for his children. It's a time for us to turn that bad childhood he had around. What are your suggestions in getting past this?