I'm sorry for the pain! I've had a lot of trouble and what felt like unending pain with teeth pulled, failed root canals, then extractions, then 2 implants. Now I'm okay. Don't give up but find a highly rated "periodontist" or "Oral Maxillofacial Surgeon". Someone else also commented on a Mayoclinic chat here that it is important that they put you on an antibiotic and a prescribed extra strong and effective mouthwash to help safeguard you against the necrosis problem. You've probably read or know all these things. I do hope you get relief! I'm 73 too and I know things can be more complicated than we would like but hopefully where there is a will there is a way!