Pregnancy sex

So I have a son from a previous relationship but my husband has brought him up since he was 1. We have tried for a while for another baby and I'm now 17 weeks pregnant. I'm really happy but he just seems to have gone really distant when I ask him about it he just says he is happy but it's ages away. I'm working full time in an active job that can be unpredictable and my last shift I was there for 24hours with a 6 hour on call sleep break and had to lock myself in a room to prevent being harmed. When I got home the next day I was exhausted and didn't walk the dog and didn't do much housework and he went mad that I'm using pregnancy as an excuse to be lazy. I've shown him real books etc that you really do get tired and have trouble sleeping etc and do sometimes generally feel rubbish but he doesn't seem to believe me and just tells me how tired he is. Aside from the lack of support, he's also admitted he finds my pregnant body "gross" and won't be intimate with me until after the baby is born. He doesn't mean to be nasty in what he is saying and he really is usually a lovely kind man I just don't think he understands. I feel so alone in this like I've lost my best friend and I'm just amazed at how badly he is dealing with it. The first time I felt baby move I told him and he said "oh" and carried on watching tv. I don't know how to deal with it anymore and I can feel this gap between us getting wider.