Cheated on during pregnancy

I was cheated on during the pregnancy of our 3rd child and apparently previous to even getting pregnant. I found out through looking at app subscriptions on Apple; not only did I find conversations and photos with women on Snapchat but he’d also been paying subscriptions to gay dating/hook up apps. I feel completely destroyed & I have no idea how I’m going to afford living in maternity leave and after. I feel so trapped, alone, & depressed.