A little more than two weeks ago, I made the mistake of wearing flats to work. I work as a nursing assistant, so I'm running around and on my feet for 8-8 1/2 hours a day. About 2 hours into work, my feet started hurting. Immediately upon coming home, I took the shoes off. However the pain in my left foot has persisted. It gets so bad at night that I can't sleep, because if I turn a certain way, the resulting pain wakes me up. Range of motion is very painful, and I can't turn my foot all the way to the right because of the pain. Since that day, I've been sneakers that have good support, so I know it's not due to continued irritation.
I would just like to know what's going on and how I can fix it.