No sex. Is something wrong with me?

My fiance & I haven't had consistent sex in over a year. There's a lot to it including illness, pregnancy & of course Postpartum healing. We also moved to a new house when our son was just 1 month old. But now our son is 6 months old & we may have had sex twice. I have absolutely no desire. Like it's not him, but I don't have the urge or feeling. I don't feel in the mood. I'm usually just tired or irritated honestly. I've never had a super high sex drive but this is bad & I feel bad because how are we supposed to get married & we're having these issues?