Hi Mylife.
I have almost the exact same problem with my left foot.
Came on a few months ago, I saw my Diabetic Dr who said I have an infection in my foot and gave me a cortisone injection which was very painful. This made my foot throb for about a week, and then it eased off.
About 3 weeks later it happened again, but went in around a week.
Now I have had it again for about 3 weeks, its the arch and ball and it feels sore, I also get pins and needles in it quite often, and it was going numb a lot, I also get pain around my ankle and the bottom front of my shin feels a little numb also. I will be visiting the doctor again this week to sort it out because it isnt normal and its starting to annoy me.
I have no idea what it is by the way, but hope you get yours sorted out.