Does this sound like plantar fasciitis?

[garlictwist]

Out of nowhere today I was walking along and my right heel started hurting. Just like that.

It's so painful, even at rest. There is a tender spot that hurts to touch but also the pain is diffuse and kind of all over. I can hardly walk.

It does sound like plantar fasciitis. Is it more painful when you get up after resting? Mine was worst when I would get up in the morning but would ease up when I walked more. There are stretches you can do which could find on the internet or roll the arch of your foot on a tennis ball or frozen bottle of water.

It does indeed. If you search it on Mumsnet, you will find loads of threads with useful advice.
I have it too and it can be incredibly painful, particularly when you've been sitting or lying down for a long time.

It's only started around 9am this morning but I would say it's hurt constantly all day. Even now I am lying in bed and it's throbbing.

I just don't understand how it could just start out of thin air and be this bad.

Is the pain underneath your foot or along the back? It could be Achilles tendonitis