Bad Heel pain and no idea?

Your best bet is to see a podiatrist - they specialize in treatment of feet. I have had this same heel pain you describe and was referred to a podiatrist. An X-ray of my foot revealed a bone spur - very common foot problem and extremely painful.

My podiatrist told me that they used to do surgery to remove these but no longer do so because they can just grow back. The only treatment option I had was to get a cortisone shot. I have had these in my feet and be aware in advance that cortisone shots in the feet are extremely painful when being injected; however, once the injection is over they do relieve the pain for a couple months. I also was told to purchase over the counter orthodics to put in my shoe to cushion my foot and relieve the pain. These did help. They are the gel kind you can find in any drug store.

My bone spurs - had them in both feet - eventually did go away on their own.

I struggled with this recently. It could be what is called plantar fascitis or a heel spur. I am not old yet, but my heel hurt every time I took a step, especially when I first got out of bed. My whole leg began to hurt because I started walking oddly to compensate. I purchased some Birkenstocks, and for a while my foot still hurt, then it hurt only when I went barefoot, and now I can actually walk barefoot for short times without pain! The Birks are sooo worth the 100.00 price tag.

This could be something simple like a stone bruise, which will heal itself in time, or it could be a plantar wart or spurs. You'll have to seek medical help-GP then possibly podiatrist.