No problem! I’m far from a legal expert, but it sounds to me like your dentist has made several mistakes: leaving the root in your gum (malpractice/negligence), ignoring your complaints (leaving YOU to demand/order the x-ray yourself) and all the pain you’ve experienced in general. This combination sounds like you definitely have a leg to stand on, which is why, if I were in your position, I’d talk to a lawyer. Search “dental malpractice lawyer” in Google to find some possible options.
Your dentist should have malpractice insurance, so you shouldn’t feel bad about suing him as it wont come out of his pockets.
Good luck, and let me know how it goes!