Believe it or not...your situation ISN'T that unusual. Come join the group over there and you'll see you aren't alone.
BUT...it sounds to me like she's ashamed of sex. Like she was raised to think of it as "dirty". She probably doesn't even masturbate herself, wouldn't think of it...because "good girls don't do that."
DON'T let anyone talk you into doing anything you don't want to do. It's easy for others to tell you to cut your losses and get out of the marriage. But if you love her, as I suspect you do since you married her...things like this CAN be turned around.
