Can someone advise me on this situation

I'm 17 weeks pregnant and seriously have had little to no sex drive though out this whole pregnancy so far, and now that my SO has ringworm on his back/stomach/chest/ thighs/and legs it seriously makes me want to stay farther away from sex with him. He's accused me for the past one and a half weeks every single day that I'm cheating on him and says somethings up for not ever wanting to have sex with him and that I'm probably getting it somewhere else. Like I'm still intamite with him and give him my attention, but I just have a really low sex drive and am grossed out by the ring worm because I'm not trying to get it (yes he's treating it). I don't know what to do