I think this sounds like a problem I had several years ago. I went to a physio who gave me exercises and I also had a tennis ball which I rolled under my feet. The physio said they could inject with cortisone but it would be painful. Shortly afterwards I went on holiday and 2 weeks of lying around and swimming in a coool pool made such a difference.
I remember suffering from this when I used to exercise years ago and recently started a fitness regime - I'd say I haven't exercised for 15 odd years. The trouble is the terrible pulling pain under both feet - I assume its muscle that's being stretched (could be part of calf???) I have to stop and move feet around again. I have special arch insoles in trainers but is there any exercise or stretch I can do to elevate this? It's a horrible pulling pain that stops me in my flow - anybody help?