I think it might be helpful to make an appointment with a sex therapist (or MC who has a lot of experience in sexual issues). Even if she's against doing this, you don't have to tell her it's to "fix" the situation since she seems to think it's okay the way it is, just explain that you both need to go in order to understand what's going on.
Most people would probably agree that physical intimacy is an important part of a healthy marriage.
