Feeling resentful and guilty

My partner and I have been together for about four years. We are having our first baby in July, im currently six months pregnant, and although I’m so excited and thrilled, I’m also really resentful for the loss of the relationship we used to have. I would even say I’m full of grief at this point.. crying every night and day. Thinking about it all the time and having a hard time appreciating and loving this stage of my pregnancy journey. Even before finding out about the baby, I felt he was losing interest in being intimate and having sex, which for me is hard because it was a huge part of our connection for the first few years. Now, he would rather look at porn, and although minimally, it still really has affected my self esteem. I’m really struggling here, feeling resentful towards my growing belly, feeling hurt that I’ll never be looked at again as anything other than a mother, and then feeling incredibly guilty that my son has to have a mother who thinks this way. It’s feeling like an endless cycle that is getting really hard to get out of. I’m also terrified at what my body will look like and how my mental health will be after pregnancy. My husband works three weeks on and three weeks off, so our time together feels very limited, and even still he isn’t interested in sex with me . And yes, I have talked to him about this. He is kind and loving and swears he wants to make it better and work on things - but then there’s no action towards it. I’ve made a promise to myself that for the next six months I won’t even ask for sex due to not being able to take the feeling of rejection anymore, but the truth is, I don’t think he’ll even bother wanting it by then. I understand this seems incredibly shallow and not important, but to me it is. Has anyone experienced this and what have you done? Thanks.