Don't know what to do

I've been with bf for over 9 years and we have been ttc. Well he cheated on me, got the girl pregnant, and is trying to juggle having a newborn and our relationship. I'm devastated and having a hard time trusting him whenever he goes to take care of his newborn. He tells me he has no desire to be with the mother that it was all a mistake. I'm trying to hang in there because I love him despite his faults but I don't know if it's all worth it.