I experienced sudden electric shock when I touched my foot.

I experienced sudden electric shock when I touched my foot. marked area in the picture. It started all of a sudden last night and I wasn't able to touch that area with my fingers. If I touched the skin in that area, I immediately felt an electric shock. Never experienced this before. It felt like a big electric shock when I touched that area. No swelling or redness. I tried to stretch and that was painful. Not able to walk normally. It was giving me electric shock and pa