You posted this question quite awhile ago.. I hope you got to the bottom of the problem. But if not, I'd like to tell you what I think about all this...
(It's totally Mental!!!) I have had those same feelings about sex at times... and no, nothing bad has ever happen to me. I've never been on medication, or had a physical problem, I'm not gay or into pornography... and I love my Husband very very much, I'd never cheat on him, he's tall dark and handsome.. so sexy, but I'll tell you the truth, sometimes I think "sex" is a discusting thing to do! 
I don't get it! It really is a weird mental problem. Which prompts me to ask you - to ask your husband, no offense please, .. but does he smoke some, or a lot of pt ??? Because 'mentally' speaking, I've heard it does have potential to ruin your mind about sex... at least for some people.
If you work this out with him, one way or another, can you let us know when you have some time? I'd like to know if this weird feeling can end! Thanks! 