Hi bchristine,
I just want to say that I am so sorry to hear about your ordeal. I can't help you unfortunately, but I can relate so much to your story, as I am going through a similar experience myself. Even our timelines are similar. Like you, I kept pursuing quite a few dentists and despite that, I am also finding that dentists and specialists keep dismissing me and telling me that all is fine with my teeth - all while I keep getting weird ongoing eruptions of symptoms. I cannot read my xrays myself, they are telling me all is fine, but my symptoms and how I feel are telling me the opposite. It doesn't help when someone you are paying to help you simply ignores you (to summarise it brutally). I cannot believe that experienced professionals (like your long term dentist) can keep missing decay or infections on your teeth. Or, are they truly not seeing any problems?
Like you, seems like my dentist didn't properly clean the area after the extraction either ... Hopefully some day some oral surgeon will take a proper look and do a thorough clean. I just hope it is not too late and both you and me don't have to keep living on antibiotics in hope that they could at least somewhat prevent the infection to become more widespread.