Single mom's and idiotic baby daddies

How did you guys deal with being pregnant again but not being with the dad anymore? I left my ex right before thanksgiving and found out I was pregnant a couple days later. Ever since then he's has been so rude to me. We can't even hold a conversation anymore. He doesn't want the baby and he says that's why he treats me like that. I offered him to walk away and he said no. Note this is baby #2