Why can't i get over you is it because we have a child together? Which is my first

Everytime i think about you i wanna cry, i think about going to sleep and waking up to your face or you rubbing on my belly and talking to our baby. I think about you making me laugh i think about when you first moved in. But as i write this i cry because i also think about you lying to my face, sleeping with other females unprotected then coming and laying with me. You picking someone who made the beginning of my pregnancy hell and then you claimed i was the reason you're with her. I constantly think about how u told me it was me you wanted to be with yet told her you wanted nothing to do with me. It hurts every time i think about it