What is periapical abscess? How to treat

I have lower jaw pain under ear and side of the ear and neck for 8 months now. Went to dentist and he took CbcT scan. Suspect fracture in #46. Went to Endo, he couldn't see any fracture. Did rct as that tooth is sensitive, sore to tapping, biting. Still same symptoms in jaw,neck. Endo tapped on crown yesterday, it hurts.sore and hurts to bite on bite paper. Same symptoms after rct, crown. Dentist want me to extract tooth.endo want to do re-rct. I don't know how to proceed with. Got cbct report from Radiologist on my own.it said periapical abscess.both endo, dentist didn't say anything like that.do I have abscess for so long? got 3 cbct scan so far. One cbct for tooth #46 in June at dentist. One cbct for TMJ in tmj specialist in September. One cbct for tooth #46 in endo office last week. tooth#46  cbct Copy of cbct scan.zip Tmj cbct Tmj cbct scan sep Report for #46 Report tooth#30 - Google Drive Reports for tmj cbct CBCT report TMJ - Google Drive .did they both miss to see abscess?help