Hi K.:
It is very common to have soreness and tenderness after stopping breast feeding and pumping. Milk builds up in the ducts and there is no release. You will feel sore for about a week to 2 weeks. I used to take very warm baths and tylenol for relief which worked quite well. I breast fed a single 17 years ago and twins 13 years ago. Believe me, the soreness will go away as your body realizes that you won't be feeding anymore. There used to be a medication to help stop the milk, but I don't know if it's still available. My advice, just bear with it, lots of warm showers and tylenol if it bothers you. It eventually will fade away.
I'm a newly divorced (yahoo!) mother of the best 3 teenage boys on the planet, 17, and twins 13. We have just rebuilt our lives from Canada to Texas with our family about a month ago.