Sexless marriage

UPDATE: Turns out he was cheating on me. I found out yesterday.

So I just gave birth to a beautiful baby girl two months ago. And had amazing sex with my husband up until we got pregnant. I can understand how afterwards he was cautious because in his mind he thought he could cause a miscarriage but we still had sex every so often until about mid-February. He made a comment that he could feel a ball in my stomach during sex and I think he was concerned that he would put too much pressure on my stomach during sex. But we haven't had sex since then. I have brought it up but he keeps saying that he is just too stressed to have any sort of sex drive. I have made myself known that I am always in the mood ready for him but I am drowning here. We have been married since June 2017 and I never imagined myself in a sexless marriage. Is this something that will eventually pass or should I be worried? I am at a loss. I just really want to have sex with the love of my life again.