What Causes Pain In Coccyx And Joints?

Hi, I have been having pain in my tailbone and it is a throbbing pulsing pain, and at one time it traveled up my spine and into my temple. I went to the Orthopedic Doctor and he said it was caused by stress, I was also diagnosed with Osteoarthritis, which I have in my hands feet and at one time they said in my knees, now this doctor says I have no arthritis, if not what is causing me all this pain in my joints. Please help me.