My own insecurities may hurt to get past it?

I have been with this boyfriend for almost 2 years. After about 6 months into he wanted to break off due to the distance apart we were (30 minutes). Over a few more months, he decided he wanted to break it off because we were arguing a lot. Then said no he wouldn't when I asked if we could get another shot. So almost another year later, we have child on way, he wants to buy house together, and he finally gave me keys and 24/7 access to his house. I know I have insecurities cause of this but...I am too scared to get close to him for fear of breaking up in just another few months. After he did this to me now, I don't trust him not too again. What do I do...I can't live day to day with this insecurity?