Husband stopped having sex with me

So, my husband and I have been very active all the time we would have sex about 4x a week. The past 3 weeks he completely stopped having sex with me and it was so weird to me because he is a horn dog. I didn't say anything and just waited... before the max we would go with no sex Would be 2 days? ... so after 5-6 days my mind was taking over me and I couldn't sleep wondering why he wasn't having sex with me. So i initiated sex, he went ahead and moved my hand away from touching his privates although he was hard and I stopped and really thought wow..what's going on? He then kissed me and said that If we did it he was gonna have to put a condom on (umm we've never used a condom ever!?) I'm currently 4.5 months pregnant with our 1st child. He told me that he had got a cut from last time we had sex on his dick and that it burned ( I didn't question much after that, nor the fact that how is taking 6 days for it to heal?) we used a condom and he could not go and was blaming the condom. After forever he finally went.... and that was it... now it's been 8 days. He hasn't approached me, touched me. Nothing, I can't even sleep at night wondering why. Like I said, this is completely different from what it was 3 weeks ago. I get a whole bunch of mixed thoughts and feelings ... like perhaps he is cheating on me, or because I've put on 25 pounds while pregnant he no longer finds me attractive. Idk ... I haven't been able to sleep at night. He is such a horn dog, if he isn't getting it from me where is he getting it? Am I really not attractive to him right now? Is he cheating? Did he catch something and that's why he put a condom on? How long does a cut on the dick take to heal ?