Painful, feel for you mate.
Yup, I've had/got it. Previous injures to foot/ankle and of course that was the one that got it worst. I did, as a desperate measure, have a steroid jab in it, that's an interesting experience, take it from me.
It's supposed to be a self limiting injury, I was told up to 18 months. In my case it was a bit longer and very occasionally I still get the odd twinge. The annoying thing is it didn't matter what footwear I put on, one day it would be ok in one pair and the next day, same pair, excruciating again.
Lift your heel up in your footwear, I made a wedge from some old insoles and put it under my footbed.
Physio helps, roll a tin food can forwards and backwards under your foot, ice packs, stretching by pulling your toes up towards you, etc. There's loads of info on the net as it's a common injury.
Good luck with it.
P.s. It's Fasciitis