Relationship changes

We had our baby 5 days ago, she's absolutely perfect in every way I love everything about my little girl and I wouldn't change a thing about her. 
I had a c section so I haven't been able to do a whole lot for myself, if I drop something I need help, pulling my pants up takes effort, getting in and out of bed or up off the couch takes a lot out of me too. I'm also trying to breastfeed and my milk is taking a little longer to come in, the doctors said it's probably because of my thyroid issues on top of all the trauma my body just went through. So right now we're supplementing at the breast and I need help with it, trying to get her to latch and pump the formula at the same time is impossible so I need my boyfriends help. He's just so grumpy about everything, and it's to the point that I dread having to feed the baby every two hours because he gets so upset with me. I haven't asked him for help with anything today because I can't handle him snapping at me. I know he's tired and a new baby is a huge change, but I'm tired too. I don't know what to do.