So heartbroken and confused, can anyone shed some light?

Well my ex and I have been together for 8 yrs in those 8 yrs we have had 3 break ups, the first one he came back and asked me to marry him but before we could get married we broke up again, this one was 5 yrs ago where he actually got into another relationship, but after 2 months came back, but I was pregnant, so I know that is the only reason he came back..but since then we have been fine. I lost the baby so we have no children we both want children badly, in between that time I got pregnant again so happy we were..but I lost it..then I closed up and refused to ever try again.

Well, 4 months ago we broke up again, but a month later started seeing each other and sleeping together it was like we were together but neither of us talked about the relationship, or said let's get back together.
Now during the past 3 moths he has been on me about wanting me to get pregnant again, I said not without commitment cause you should have a baby with someone you love and want to commit to but that I was ready and my body is healthy and I can have a baby now..he said well I am 30 now and I want a baby and we have 9 months to work all that out. But he would not say anything about actually commiting to me, and he also kept thinking I was wanting some other man and got hurt about it and didn't think I wanted a baby with him..but my point was not until you commit.
Well the last time we were together he was after me again..I said not without commitment.

Ok so 2 wks later..he is in another relationship with someone 11 yrs younger than me a little party girl he met that works at a gas station that he goes into daily..I am soo confused how did he go from wanting to start a family so badly to now being in a new relationship???!! WHAT HAPPENED?? Why did he do this? Now he is acting as if I am DEAD! Like I have the plague! He has been with this girl for 4 wks now made it official on FB and all, I am no longer his friend on FB as I blocked him. :(
His sister who is my friend and also who is married to my brother, yea they met through us we had been together for a year his sister met my brother and yea they been married for 6 yrs now..well I found out that she is all telling him and the new GF how happy she is that he is so happy with her..WTF??
Well I talked to her about it and she said she had no idea we were still seeing each other and had no idea what was going on. I need insight I have not slept or eaten right in weeks! I have baby fever so bad it hurts also, and my brothers wife just had a baby and every time I hold him it hurts so bad! :upset:

First of all you did the right thing as far as not wanting to start a family without a commitment. If he had truly loved you, he would have wanted to marry you then share a family with you.

I have been in and out of a relationship with one guy for years now. At first it hurts when we break up but after a while ... life goes on. Take this time to work on you and become a stronger person ... independent and strong. Relationships come and go .. if it is meant to be .. it would have lasted. Wait for Mr. Right and be available for when he does show up ... last thing you want it to be in a relationship with a loser when your soul mate arrives.