The skin on the top of my left foot is sore over the bony, knobbly part and towards my big toe. It's only sore when in contact with fabric. My socks make it sore and lying bed on my front (how I sleep) is making it sore. It was sore enough to keep me awake. There is no bruising and no redness. I haven't done anything to damage it. What on earth is it? Can anyone help?