Lost my sex drive. How can i get it back?

Okay. So me and my husband has always had a very good sex life. I have a very high sex drive. For the first few years him and I had sex 2-4 times a day. Until I got pregnant. Then we only did it once a day sometimes we would have weeks that we would only do it 1-2 X a week. Well my baby is 6months tomorrow. I've been fighting with fevers due to dehydration the last few weeks. And it just seems like I'm not interested in sex anymore. For the last month we have only been doing it when he initiates it..(maybe once a week) and he does a great job..but that Good pain(poking) feeling during sex has just turned to poking pain. And I'm just not interested in sex anymore. Idk what's happening to me. My husband has bee. Going out of his way lately to be sentimental and romantic and I enjoy the hugs and cuddling and kisses but... the sex..I'm just not turned on. Don't get me wrong he is GREAT.. But I just don't get what's going on with me. What could cause loss of sex drive for women and how can I get it back?