Single mom

I’m having a really hard time excepting that I will be a single parent to my second daughter. I was a single mom with my oldest daughter but for some reason that was easier to accept. There was no heart break the first time. But with my second daughter there was not only heart break with my relationship but a pregnancy loss before hand. I want to be good at coparenting but I’m worried I won’t be able to fix my heart so I don’t feel cold towards her father. He hasn’t been active in her life yet and if that changes I want to make sure I’m her advocate and not treat him poorly because of my own feelings. Any thoughts on how to move past this. I start seeing a psychologist next week due to severe postpartum anxiety that I’m sure has to do with this situation.