So lost and down

I feel like a horrible person but I just can't do this. My baby is only 16 days old and nursing him is so much work. I'm exhausted. I pump too and he will take the bottle from his father but he won't sleep at night unless he uses me as a pacifier. He will fall asleep and then remove himself from my breast and sleep next to me. As soon as I pick him up to put him in the bassinet right next to me he starts waking up and gets fussy... Then screams. I get no sleep. On top of it I just am starting to dispise my boyfriend. I can't stand him. I love seeing that he loves his son. I love seeing him care for him but I just can't stand him anymore. Unintentionally he has made me feel disgusting. While pregnant he constantly made "big girl" jokes to me. He has not kept up with paying the bills and my credit score has taken a huge hit. But he still manages to pay for his supplements, gym membership, and other nonsense he wants. Meanwhile, the deal was for him to pick up the slack while I was out of work. I was suppose to be home with our baby for at least a year. But now that I feel so out of my body I want to return to work as soon as possible. Tomorrow if I could. Because I want and need money. I want to work on my body. Get back into my size 6 jeans and small tops. I feel hedious. This whole last year he constantly goes on his ex girlfriends Instagram looking at her pictures. Then last week she text him that she was in love with him, thinks about him etc. Who cares if she texts him - he didn't respond- BUT when he stares at her pictures all the time it just adds to it. Overall, I'm just sick of him. I feel resentful. I look at my baby and I feel bad- I feel bad that I want to give him formula so I don't need to worry about this anymore. And I feel bad that I wanna go to work. I work as a child care provider- so I feel even worse that I wanna leave my baby so I can take care of someone else's baby. I'm horrible. But I'm lost. I'm sad. I feel ugly.