scaredmom - I originally ended up in the ER with nearly the same symptoms, although mine were accompanied with what I am coming to find out are PACs. Regardless, I was also diagnosed with costochondritis, something the moderator mentioned. Like your daughter, I was told to take a higher than normal dose of NSAIDS (ibuprofen, motrin, etc.), but not much seemed to help. Desperately, I saw everyone from a chiropractor to a massage therapist. The massage helped; it was hard at first as the massage therapist couldn't go very deep because I was in such a fair amount of pain. After two to three weeks of an hour a week, I was seeing some improvement. Unfortunately, I was told that it generally takes 6-8 weeks to heal.
The most important thing for me, though, was finding a doctor that would listen and help me. It took three for me to find one that would take me seriously. So my suggestion to you is to find another doctor. Keep going until you can get a physician who will help you. I heard the greatest saying the other day: "Remember, it's called PRACTICING medicine; they can't ALL get it right ALL the time." And I've found that they each practice in a different way, so hopefully you can find the best one for your daughter's needs. Finally, please let us know how your daughter is doing. She will be in my prayers.