I feel like I’m failing my little guy

I delivered a late term preemie at 35 weeks. Im 4 days pp. I’m having so much trouble keeping up with pumping and feeding and he just never wants to eat. He can latch pretty well but he just gets exhausted and we keep trying with formula. My milk supply isn’t established because I haven’t been able to pump often! 2-3 hours is just too much for me. I just feel horrible and I just want little guy to be ok. I’m going to see his pediatrician hopefully today. My husband is trying to be helpful but there’s only so much he can do.