Hi Moomin
Odd thing when I read your post, I had very similar thing happen... Was NWB for more than 10 weeks, 7 1/2 weeks in cast... then onto the Herman Munster boot for another 12 weeks but anyhow when I was given the OK to start balancing weight and then onto full weight bearing, I was determined to take steps, I parked myself next to the counter determined to take those three steps to the fridge for a Pepsi... I did it after 3 failures and I was so excited, I couldn't wait for the hubby to come home to show him how I "walked"...

So when he arrived I showed him and I went down in a heap this pain came from nowwhere and it was insane...it was primarily around my heel and in the arch, I would have sworn that they left something behind in my surgery - like a knife in my heel and marbles in the arch..
I seen the OS a week later and he said the ankle was week from prior injury and then surgery and to give it 3 more weeks... stay on crutches etc., I wanted to walk but I tell ya...that pain made me stay on the crutches, I would attempt it at times but it would drop me to the floor. I found out later it was Planters Fasciities, I bought every thing imaginable to cure it... Heel lifts made of silacone, rubber, memory foam etc,. I will still in the boot so it wasn't a matter of changing shoes but I did that immediately out of the boot. I find that rolling a frozen can of soda under my foot really helps and if I stretch it out before walking then I am good, not wearing flat shoes also helps. It still knocks me down on occassion but its alot better, it takes time... patience and more time... It took about 3 months for it to settle down where it didnt' take my breath away but mornings are incredible...sometimes I crawl to the bathroom and my hubby laughs... I wish none of this on him but a week of PF would cure him of his laughter I am sure!
Try to stretch it out before you apply pressure and try the frozen soda can, sounds wierd but I tell ya it worked for me!
I wish you the best, good luck and hope your walking pain free soon!
Carol