What Causes Pain In My Swollen Thumb After It Rubbing It?

My left thumb joint is swollen like with a ridge near the base. It has been very stiff and rigid like. I can't use it without pain, especially when I grip things. Today, I accidentally banged it or shoved it some against against some wet towels and I had excruciationg pain. I couldn't ben it at all til about 15 minutes elapsed. It is very exruciatng pain if I try to bend at either thumb joint. I recently had been on 50K units of Vit D and stopped it as I felt it caused my kidneys to ache and my bones to hurt me more. Please give some advice on a diagnosis.