Exactly the same thing happened to me back in May. Only just recovered from it. Like you, I kept thinking it was alright. I didn't take a break from footie though, just used my left foot for most things. Anytime I did use my right, I would be in agony again.
So what happened? Did you end up going to the hospital or doctors? What is/was wrong with it?
I've since had an MRI and i've snapped my anterior cruciate ligament and done some miniscus damage.