Greybuffalo, I had a tooth that I need a root canal on. After the canal, for about a year and half I had nothing but problems with the tooth. it hurt off and on like crazy. I went back to the dentist and he couldn’t figure out why it was bothering me. Eventually i ended up going to a Endodontist that looked down the tooth and found a small secondary canal that was missed. She refilled the canal and it seems to be doing pretty well..  I wouldn’t pull your tooth! go to a Endodontist and have them look down the tooth with a microscope. They will be able to see if your tooth is cracked or if there is a secondary canal, and any other problems that might be going on that isn’t allowing your tooth to clear an infection with treatment. I feel your frustrations, but take your time and make sure you see a professional about this :)