How did you find out he was highly sexual? Perhaps he was hiding it because he may have thought YOU would think he was a freak -- or a pervert.

Who knows? Evidently you two do not communicate very well.
The same with his high IQ -- why on earth would he hide that? For fear that you two would fight about who's the smartest? Or would be in competition? Again, who knows?
Communication is very important in a marriage, and you two just don't know how. Perhaps some couples counseling would help -- cause you two should be able to talk about ANYTHING and it's obvious you can't. You should be able to bare your souls to each other and have an open and honest relationship. It's sad that you don't.

Your marriage would be SO much more fulfilling if you did. Why not try some counseling and learn HOW to talk to each other without feeling threatened. It is more than worth it -- it has saved MANY marriages! You don't want to keep living like this for the next 20 years do you? I doubt it.
God bless and please take care! Hugs, Lee