You may want to consider that you will not get the answers you are hoping for or any explanation. It really won't change anything. Once someone moves on, there is no reason to spend any time or effort trying to figure out the why's or try to explain yourself. I can only speak from the other side of the coin. Sounds to me like he is done and has moved on. There is no reason for him to contact you or respond - especially since you don't have kids together.
My 2 cents is see a personal C to help you thru your feelings and to assist you in moving to the next stage of your life.
