Plantar fasciitis is agony, literally. I had it when I worked in a hotel wearing uncomfortable hard shoes for 8 hrs a day, 6 days a week.
When you are on your feet, your feet feel numb initially, and then it's like your heels are standing on hot coals whilst being pinched. And there is nothing you can do to relieve it.
I tried putting my feet in cold ice buckets, with bicarbonate of soda added. All it did was remove dead skin, the plantar fasciitis feels like a pain in your bones, nothing relieves it.
I have been working an office job for almost 12 months now and my feet are soft again but if we go into town shopping, or standing at a gig for a few hours, it flares up again, it is like torture, nothing relieves it.