No sex drive

Catrina • 25. Married to my other half. 5-15-15. 1 angel baby named River. Daughter named Remington. Son named Journey.
I'm 20.5 weeks and I literally have no sex drive and my husband is starting to get frustrated. 
Anybody else this far along and it just hasn't come back? 
We lost a son at 20 weeks so I'm naturally anxious during this pregnancy, I'm exhausted always, my sciatic nerve hurts daily, can barely sleep... I'm just a mess... On top of feelin insecure and like I'm a pig....