I Have A Spot Near The Inside Of My Heel

I have a spot near the inside of my heel that is red and a little purple, and extremely tender. I have been forced to walk on my toes the last few days because I cannot put any weight on it. It also appears to look as if it has a callous in the center of the spot. No Opening, puss etc. I went to the doctor a few days ago with a severe headache, fatigue and stiff neck and back, she examined the spot but didn't think it was related. I have been taking Tylenol and alternating ice and heat but nothing seems to be helping.