cheated while pregnant

so this might be triggering for some people so fair warning.

i found out i was pregnant in june & not even 2 weeks after telling my SO he went & cheated on me.. i only found out because of the hickey on his neck. so i left him but even though i know i deserve better & never deserved that i miss him so much. & it all hurts so freaking bad. & at the end of august he started texting asking about the baby & how everything was & blah blah blah but my problem is every single time i talk to him i wanna throw myself off a building but i think about my innocent growing child & feel so guilty & enraged that id ever let him make me feel that way so i know its slightly the hormones but i find it so unfair that he gets to just pretend like nothing happened & i cant refuse contact with him because then im seen as a monster mom keeping the dad away because of spite but how is it he can just cheat on me & then leave for 2 months just to show back up & act like everything is fine !!??? i just wanna throw myself on the ground & kick & scream & cry & how is any of this fair?!?!?! i dont want to be the bigger person anymore. part of me wishes he was dead so he couldn’t keep doing this & part of me wishes he would just apologize & change & we could do this together & ugh.. i just want to stop feeling this way.