Muscles in the foot or something else?

For the last couple weeks, I've had minimal-harsh pain in my foot. It is basically all around the ankle area. Working at a daycare, I am constantly on the run, fetching kids, stopping fights, etc. However I've been working there since December, and this pain just started recently. It is causing me to limp, yet the pain comes and goes (usually just on levels of pain). So in the morning it can be very light to none, during work be minimal to dull, elongated pains, and then leaving work and at home be a harsh long pain. The only way I have combated it is using pain pills and products like icy hot. Could this just be a muscle pain...or something else? Anything else I could try to make the pain go away?