OK, I've never had this pain and have no idea what it would be, and a visit with the Doc would be advisable for sure. Having said that, I'll see if I can ask you some questions that may help you discover the problem. First, check your shoes... any pinching or strange spots? Are you using good running shoes? What about your socks? Any toe seems causing issues? What about new callouses that you haven't noticed before? I've had some since I was 15 and periocially, I have to file/shave them off or it will hurt. However, typically, this is not the horrific sharp pain that you're desciribing. What about a... I think it's called a corn? The thing I'm talking about is like a callous, but grows INWARD and can cause very sharp pain. A doctor may be required to care for that, but it might also work to file it. My father-in-law has gout and he swears by Cherry juice to stop the pain... I have no idea if yours is gout or if that really works, but it seems to for him.

I'm out of ideas after that. Good luck my friend.

Mark