GA, I'm not surprised you're finding this difficult. The last thing you need with a new baby is a man acting like an infant too!
I'd second what the others say about men finding the adjustment hard. You have carrired this chld inside you for 9 months and had all that time to get used to it. Your DH obviously knew he was going to be a dad, but I think for men it can eb a much more brutal shift - one day it's just the 2 of you and the next day there's 3! As I heard someone say the other day, "You are now in a non-negotiable relationship with something that has no Off switch"!
He may also be feeling jealous of the baby and its demands on your time. I have no time for this attitude myself, but I know it is common.
He may also dislike the physical act of you breastfeeding - ie feels your body is "his"
He may just feel generally displaced by the baby and has decided "Sod it, she and her mum can do it fine without me, I'll just carry on as normal".
All of these things are common reactions experienced by my friends' or my DH after a new baby.
In your hormonal, tired state, it is very hard to think straight about all this. I would say, go off to your mums for a couple of days if you can, to get some space. Then, when you do sit down to talk with DH, try very hard not to get angry (whihc you have very right to be), but instead approach it from the "I really need your help, I can't do this without you" angle. If he is feeling rejected and unloved, he needs to hear you tell him that only he can give you the help and support you need.
He may not do things with the baby the "right" way, but try to let him find his way, or at least not criticise him too much. My DH still says he hates it when he feels I'm always telling him he's doing things wrong, and our children are 3 and 7 months!
I really hope things get better for you and your DH gets the right idea soon. Keep us updated