@neoboy
Consider a plastic bottle filled with water in the freezer and roll your arch with that. I found it helped a lot.
Never really sure of the cause, i know some people suffer from it again it seems to linger forever but i usually just get it for short periods and it's never too severe.
Looking around the Internet, apparently it's common after ankle injuries, my other foot is fine. In fact looking at my foot, there's almost a thick line like swelling going from my ankle to the bottom of my arch.