Get a wheelchair.

I have this as well. Keeping the muscle warm, ie gentle stretching and exercise helps with the pain. Resting it entirely only allows the muscle to continue to cramp and get worse. It can take years to settle entirely. Average is around 2 years. Sucks to have OP, good luck with orientation!

Good luck OP. I also say get a wheelchair if possible.

A wheelchair might help for he short term, but in the long term you should invest in some new, high quality shoes that actually fit. Maybe even get customized orthopedic inserts to replace the default ones with. Exercises will only help so much if your shoes are part of the problem- which, if the condition started recently, is likely. I'm saying this from personal experience- the arch of my feet is so high that I have to walk on the balls of my feet when barefoot to avoid pain- and meant that a lot of shoes caused me pain because my arch wasn't supported properly for the design of my feet. I went through a bunch of therapy and exercise regiments that didn't help because they never checked what my shoes did to my stance. So, if you can, seeing a podiatrist and/or orthopedic doctor will probably help you a lot in the long term.

I have that too!! Mine just started a month ago. The worst part is there's no cure for it except to adapt and live with it. I suggest some good shoe inserts from footsmart. You need arch support!