What Is The Treatment For Pain And Numbness In The Umbilicus?

Hello. I am a female, 46 years old and experiencing pain and numbness just to the left of my umbillicus. It has started out as periodic pains (like my muscle is tearing or ripping a little bit right under my skin) with some associated pain. Now I have pain to touch (like a bruised feeling) and the skin is going numb. The only thing that is different is that I started taking Concerta (I don't think that it is associated with that, but I don't know). I am 20 pounds overweight also. It is worrying me since this has never happened to me. It feels decidedly skin/muscle or nervous system related, in other words, it doesn't feel like bowel or internal organs. Mostly just surface numbness with a bit of pain under the skin. Help please!