"it's just that sex isn't the dominant desire for my wife."
Maybe it is. Maybe this is how she shows her sense of worth. If she has low self-esteem as you say, she might use the sex as a way of self-affirmation.
How are your day to day interactions? Any other methods of intimacy like hugs, touching, etc.?
Have you ever read the 5 Love Languages book?
Our day to day interactions are good for the most part. We call each other throughout the day, we go to lunch together often, we have regular dates out. We hold hands, we cuddle on the couch, she sleeps on my chest at night. We never hang up a phone or leave the house without saying "I love you".
Kissing might be problematic. We kiss each other goodbye every morning and goodnight every night. But it is rarely the passionate kind of kiss.
