Alea I do sympathise. I have a problem with both my feet such that I am in constant pain. I have become so used to it now that the low level of pain which is ever present is scarecely acknowledged. But it takes very little for that to trip over into agonising pain - just a walk around Sainsbury's for half an hour can do it. An afternoon out visiting a NT property means I can barely stand, let alone walk, for the next 24 hours. Because of medication I am on for other health problems, the only pain relief I am allowed is paracetemol.
At its worst yes, it does affect my mood. It can be so bloody depressing. I used to do a lot of photography, and I live in a beautiful part of the country, perfect for this pastime, but the pain in my feet has meant that I hardly take my camera out these days 