Stressyhead, don't go having anything crowned whilst you are in pain. Agree with Robin, go to A&E or ask your GP to refer you urgently.
Do you have wisdom teeth? What position are they in? Could they be causing you pain?
My uncle was in a lot of pain, had an extraction but it turned out he had such a bad infection in his sinuses he had to have an op. to have them cleaned out.
Don't understand why you are paying so much to have your teeth done. NHS dentistry is very much the same as private, the only difference when I worked at a surgery was that you could have white fillings in back teeth and there was a higher gold content in private crowns and that we made metal dentures privately only.
Don't let dentists make you think you're getting something special because in my experience, you aren't.