Low sex drive..

So had a baby feb. 2021 and I am still not back normal as far as sex drive. My fiancé makes a really big deal about us not having sex as often and has a tendency to send these long frustrated text about our sex routine changing. I’m honestly not sure how else to handle the matter. I tell him that I’m not as turned on but I offer to still do it to take care of his need. Any one got a remedy for low sex drive or tips?