My old root canal tooth is still bothering me. had it done couple years ago. what should i do?

See a dentist: You need to have a dentist evaluate the root canal to determine what the problem is. A radiograph (x-ray) is needed to see what's going on. It's possible that there is a crack or a fracture in the root, and that is why you are having pain.

See an endodontist: Endodontists are dentists who specialize in saving teeth, and have at least 2-3 years of advanced training in root canals. They are experts at diagnosing and relieving tooth pain/infection, retreating old root canals and use advanced equipment to treat patients efficiently and comfortably.