My girlfriend (call her K) is suffering from severe depression. Her ex wife cheated and got pregnant, promised K that they will be together and raise the kid together, but went back to the baby daddy( abusive ex. K now feels the loss of a son, and the loss of a family/future. We started dating about a year after they broke up, the son is now 3 months old. They tried to be friends, but it’s killing K to see the baby and her with that guy.