Perio ligament?

[Sandybob23]

Had an intense toothache last July, after the tooth ache was gone, I was left with biting pain in the tooth (#30). ( Backstory: I clench. Had root canal with similar symptoms 15 years ago on # 31 & had it extracted. )Had first part of root canal in November and second session in January. After the first part I still had biting pain & after the second part I still had biting pain it is now more than nine months since the initial tooth ache and the subsequent biting pain. I have seen two dentists besides the endodontist who I have gone back to several times about the issue.. He told me to wait until this July, which will
make it a year to see if the biting pain has gone away if not, he will redo the root canal. All drs say my X-rays & cone beam are perfect & do not see a crack. Of course, not all cracks can be seen. My question is, when I told the endodontist after the first & then the second part of the root canal that I still had biting pain ,shouldn't that have been a red flag? I am most likely not going to go though the probably futile redo of root canal 8
have it extracted. Which is lousy be it leaves me missing 2 molars on bottom right. Would a periodontist be able to help me at all with this who helps you with periodontal ligament? I’m having such a hard time between Endo‘s and regular dentist trying to figure out what to do with this tooth.