Does Re RCT retreatment helps? Help?

I had root canal on #46 in September. No infection or cavities. I had lower jaw burning pain under ear and side of neck since may month. Went to dentist, took CBCT,he suspect either tmjd or fracture in #46. I went to Endo and no fracture spotted. That tooth was sensitive to bite and cold spray. Endo did Rct. I got crown in Nov. Still same symptoms in jaw and neck. That tooth and gum is very sore since crown placed. Went back to Endo since same burning pain in jaw, neck. He tapped on the rct tooth, it hurts and tender. Gave bite paper to bite on. It hurts and sore, tender, sensitive to bite on. He prescribed antibiotics for a week to see if it helps. Does antibiotics helps for this tapping, biting pain/tenderness? He took new cbct this week and no bone loss noted. How to find fracture from Cbct? He is not very sure though. My rct filling is very narrow in Cbct. So he asked me to come back,he will redo rct with wider filling. Will that help? My dentist want me to extract it. Endo re-RCT