Need advice

I'm pregnant and a FTM.. my sex drive has gone down drastically to the point I havent had set with my S/O in three or four weeks now. I think he's started watching porn more often because of this. I caught him on his phone looking at some video of a girl. Not sure if she's someone he knows or if it was porn. Now I'm kind of concerned that if I don't get my set drive back maybe he'll leave me. Does anyone have any tips on how to get back your sex drive? I'm desperate right now.