Can a cortisone injection help with pain if you are unable to rest it?

The Corti Inject. it was that bad when the inject was preformed but it was put directly in my arches and I could not walk for a week this was a year ago, now I have cysts in the areas that the injections were preformed, now it is extremely painfull when I walk, the best thing that has worked for me with the PF is Brekenstock shoes they are expenive but it works on me.