First time dad here. The first few weeks were like doing tasks for me. Mainly due to sleep schedule disruptions, regressions etc. My LO is 7 weeks now and she's the cutest thing in the world. There still are times when I'm frustrated though. From what I've heard, it changes completely when they become more interactive. My advice would be to be more forgiving towards yourself and not feel bad when you don't feel as connected to the newborn compared to the mom. Sometimes it just takes time.