Most break ups are left with no closure, sad but true. Write a letter to him, tell him all the ways you are hurt, mad, and pissed off, Let it all out.. Them burn the letter !
It can be helpful when trying to make sense of it all. There are so many stages in life. Only you can make closure happen for yourself.
Focus your attention on your baby. That is the best distraction in the world. I'm not sure how far along you are , But maybe start preparing the nursery, pick up a adorable outfit here and there, and of course the cutest most adorable stuffed animal on the planet. Seems most all mommies do that, I know I did
Things will get much easier.