Re: Lung cancer fear? I'm 23.
A lot of what Elizabeth says is good information, including the "don't panic".
DO find a board-certified internist or pulmonoloist as soon as possible. Be prepared for them to tell you to lose weight. Being heavy hurts your whole body, as I am sure you know. It causes muscles and ligaments and tendons to carry far more weight than they are designed for, and that causes spasms and pain and tenderness. I am morbidly obese, and I know what I am talking about here.
If you can, try mild exercise every day. Sometimes getting the joints to move gently help the spasms. A nice soak in a warm tub is great too, but getting some gentle exercise is also good. Keep your joints moving so the muscles don't get weak and out of shape.
Watch your diet and reduce the amount of fat in your diet. Fat can cause diarrhea and diarrhea causes lots of unhappy things. A high fat diet can cause cancer.
It is unlikely you have cancer at your age, but not impossible. Being your own advocate is good advice, so be your own advocate by taking better care of yourself, getting a good doctor, lose weight and change your diet. Be proactive, not reactive.
__________________ death is for the living. it tells us that life is short; there is no time for meanness or cruelty.