I am a 16 year old female, athletically fit, and vegetarian. for almost two weeks, i have been experiencing sharp pains in my chest right under my left breast, excruciating migraine headaches (history of, but worse than ever before), horrible pain in my left shoulder and elbow, and horrible pain in my left hip and knee joints. I went to the doctor, which all together is a horrible physician, and without seeing me said that i had Costochondritis and told me to come back in 3 weeks. The pain has been getting worse, by the hour, and has left me to the point of not being able to get out of bed. The cold makes it worse, as does the Heat. Also when i exercise, the pains in my chest get worse and i cannot breathe correctly. I don't believe what my doctor says, and i don't know what to do. Any ideas what to do and/or what this could be?