Low abdominal Pain, severe?

It sounds like you should go to the ER, because you don't know how serious this could be. If your skin is sensitive to touch, there's probably something inflamed. It could be a reaction to your hysterectomy, who knows. To me it sounds like an infection, and that's something you must get looked at. It will only get worse, and you're risking permanent damage if you wait to see a doctor. Sorry I couldn't be of more comfort, but it's really something you need to get looked at ASAP.