Postpartum resentment

I am 7 weeks postpartum and I go back to work on March 11th. My husband works night shift on two days cycles and every other weekend. My son is NEVER content during the day unless he is eating, sleeping, or being held. As much as I love spending this time with him, it’s hard when he needs so much attention and I have so much to get done around the house and I am also full time in school still. I am building up some resentment towards my husband because he gets these day long breaks from any responsibility with our son or being able to sleep all day uninterrupted. I am feeling so burnt out and I don’t know what to do. I’ve expressed these feelings to my husband but all I get back is an “I’m sorry”. I don’t know what I expect him to do or even want him to do, but I just feel like I’m at a loss