Most sex issues are based on an emtional disconnect rather than actual technique problems. I would reccommend talking to a couple's counselor first, then maybe they can reccommend you to a sex therapist if needed.

The Mrs and I lead very busy and distracting lives that can leave us drained and uninterested in sex. One thing we introduced into our lovemaking years ago to help spice things up has been fantasies. We'll talk about it in the morning...let it simmer throughout the day...and then act it out after the kids are asleep (we hope...LOL).