Losing interest

I think my husband and I are losing interest in one another. We will be married 3 years in April and we have one child together. He will be 2 in May. We have decided to try for another child because we don’t want our kids to be too far apart. But neither one of us are really interested in sex. We never really crave it with one another. Idk about him but I do want sex at times but then when I think about having sex with him I no longer want it. I hate that. I love him I always have. But we have no sexual relationship whatsoever. We can never really have sex multiple days in a row. We have sex maybe once a month. Twice if I’m lucky. I had a positive ovulation test yesterday so I wanted to have sex 3 days in a row to try and get pregnant. We had sex yesterday. I wasn’t enjoying it and idk if he enjoyed me or just the fact that he could have some enjoyment. Anyways so we were trying again tonight and he couldn’t stay hard. He kept saying “idk if I can do this tonight”. So of course I get upset because I think it’s me and the way I look because I am fat. We’ve had that discussion before. But I honestly think we’re just not sexually attracted to one another anymore. Idk what to do. I love him. But I’m not sexually attracted to him anymore. I feel like he feels the same way. What should we/I do?