Until you can get to a doctor (orthopedist or podiatrist, we each have our favorite, to my mind more important is whether they do anything for you rather than what their title is) do the following.
Use ice to ease the pain, a bag of frozen peas works well or some slightly mashed ice cubes in a ziploc bag, just snuggle your heel into it, use a towel in between if it's too cold all at once. Chemical gelpacks for picnics and etc. can be too much cold, advise staying away from them.
Stretch your feet before you stand, scrunch your toes under then flex like you're on tippy-toes, point your foot like ballet then pull your feet back flat and feel the stretch in the calf. Do this several times to gently exercise the tendon so it stretches rather than strains when you stand up. Do this in bed too.
Don't go barefoot, wear good supportive shoes always, get some cheap sandals or plastic thongie things to wear in the shower, make sure they have an arch support or wrap your arch up in an ace bandage first. If you have no arch, stay out of high heels, if you have a high arch wear a medium (1 1/2 inch heel).
Try over the counter inserts, Birkenstock blue is very popular here, get them fitted by someone knowledgable not the kids clerking at Foot Locker or a mall store. I have nothing against mall stores, but these folks aren't trained to fit shoes for problem feet, it's not fair to expect them to do a good job at it. Once you know what size you need and what brand, go ahead and buy them where you can, but get fitted properly first.
If your doctor tells you to live with it or wants to immediately put you into custom orthodics or surgery, leave and go to another doctor. Cortizone shots should be given close to a last resort, and only three times maximum, don't expect them to be a cure.
Come back and tell us how it's going, we care, even if we can't help ourselves we feel better if we can help someone else.
10:16:52