person A: I recently had a baby and now none of my friends want to hang out with me anymore. 
person B: Congratulations!  That's awful!  DO they not have kids themselves?  Its a pretty typical thing to happen when you're the first to have a baby among them and they don't understand that lifestyle. I've been there.
person A: Well_comma_ the father also left_comma_ so for me_comma_ I've just felt very sad and isolated
person B: I'm so sorry. My sister was in the very same situation as you and I can tell you_comma_ she made it through and her daughter is 9 now.  She kept taking a day at a time and working hard and went back to school to become a nurse. You can do it to. Find some true friends who will support you no matter what. 