Root canal and crown?

Hi, I had a filling replaced in late October. About a week later, my tooth became very sensitive to biting. If I bit a grain of pepper, it would send a very intense pain in my tooth, but stopped as soon as the pressure was relieved. The feeling did improve over the past two months and now it is still sensitive to bite, but nothing like it was. Also, I do grind and clench my teeth at night, but it's never caused me pain or discomfort, just some wear on my teeth. I don't drink or smoke. What is the likelihood that I'll need a root canal and crown? The sound and feeling of the drill is like nails on a chalkboard to me and even when numbed, I can still feel a sensation from the drill that sends me into cold sweats. I do have an appointment with an endodontist, but I'm dreading this. I know it's case specific, but how often can you correct the biting sensitivity without needing a root canal?