@Goonergal Over the last few months, I've been doing a mixture of gentle stretching exercises, stopping walking when feet hurt, but not stopping completely, and added some additional heel insoles from time to time which also helped the heel pain. I've never been much of a hillwalker so that gives me more incentive to stay that way! Though, the steps I had to climb yesterday at the canal tunnel were worse than any hill! I really didn't fancy the long, dark, wet tunnel and I'd been getting a bit of grief from men who were fishing - illegally I presume as they were clearly rattled by my presence. Either than or they were misogynistic enough to think women shouldn't be walking the canals alone...I was going to take some photos at the top of the steps as the view was spectacular, but they were still giving me verbal grief, so I didn't. I know where I was and I want to pick up from there another time, so will get a picture then.
I also had been sticking to the same brand of walking boots, but have one pair now of a different make to alternate with. I'm also trying to remember to wear shoes with slightly raised heels. Which is unusual for me, but it has helped as well.
@DJC3 - I also hope the horse is OK. A couple of other passers-by who know the area recognised it and assured me it was fed and looked after, which I could see as it was clearly healthy, if very muddy! But, it was clearly stuck somewhere it shouldn't have been!