Something seriously wrong or just arthritis?

Alrighty so about a year ago I accidentally squished the living hell out of my hand and I didn't go to a doctor because it didn't hurt at the time, in fact it didn't hurt until two months latter, and since then its been constant. I work at a very hands on job and the constant use of my hand seems to have made it worse, there a odd hard spot on the palm of my hand that when I hit it just right makes my whole arm hurt so bad I want to cry or throw up. If I work more then six hour straight I usually go through 12 Tylenol so I don't just crumple to the ground in pain but it still hurts even then, so what I want to know is, Is there something still messed up in my arm or is it just really bad arthritis that I can't do anything about? Anyone with any ideas feel free to share