Do not worry about fibromyalgia. That's a big problem for old people like me. You're 17 and in pain, that sux. I had a similar condition when I was your age and it stemmed from posture. It sounds like you are suffering from a form of neuralgia. Neuralgia is typically defined as being a shooting pain typical in the myofacial area aka the face area but it can also happen in the arms and ribcage. Ever hear an old person tell you to take care of your back? That's because your back is essentially the most important area of your body and without a strong back, other ailments can occur. You may have a case of scoliosis which could be the culprit to your nerve pain. Scoliosis is an annoyance that can cause many physical ailments but it's manageable. Don't get discouraged but do ask a doctor, PE teacher, coach or even a personal trainer at your gym to check you for scoliosis. Most cases are apparent to a spectator if you arch your back so it's rounded like a cat pose bending forward to touch your toes. This way your spine can be traced to and the root of misalignment causing the pain can be pinpointed. Either by a doctor, PE teacher, etc or your own online research, you can get a lot of useful information about stretches you can do to help alleviate your pain. Thing you can do to fix your proble are the following, Watch your posture, take a dance class like ballet, do yoga, sit-up - get yourself a strong core/abs that can compensate for any misalignment in your back, lay on your back on a hard surface. The process isn't a quick one but it's better than feeling helpless in pain. Implementing these excersizes in a daily routine will prevent future problems like fibromyalgia. In 3 months, you'll see great improvements but if the pain does not go away then I suggest biofeedback. Try not to take pain medications but if you have to, I recommend a doctor to prescribe you a low dosage of neurotin (this prevents shooting nerve pain episodes) or zanaflex if your nerve pain created onset long lasting spasms. You can also alternate a hot compress like a hot damp washcloth or heating pad with an ice pack every 10 minutes until the pain calms down. It works!
Go to a Rhuematogist- and tell him/her where exactly the pain is when it's happening ( and where it jumps to). If those pain points match enough of the fibro trigger points- you win the prize. I spent a REALLY bad 3 years with Drs telling me I was crazy. Fortunately, I was finally diagnosed with Fibromyalgia. No cure, but better with current treatment (Lyrica and Cymbalta). DO NOT allow them to just say you're depressed, and do NOT allow them to put you on Elavil (put weight on I've never been able to remove.
As with Any chronic condition - what makes life worthwile is HOW you live it. Sense of humor is key. If you can still laugh, ANYTHING is live able - and life is WORTH living, even if you hurt.
Those sharp shooting pains in your wrist could possibly be carpal tunnel syndrome. Physical therapy (stretching) can help alleviate it most of the time, along with some anti-inflammatory medication like Ibuprofen. The pain under your chest could well be indigestion/gas, acid reflux disorder, anxiety, or even pleurisy. Those thing will need to be diagnosed by a physician after he examines you, draws blood work to assure that it's not related to you pancreas or liver, and possibly orders radiologic testing like ultrasound, CT, or Upper GI testing.
I understand that your parents may not be able to afford all of this to be done, BUT, any parent I know of would prefer getting to the bottom of this issue, since it's causing you so much pain. YOU MUST tell them and offer them the chance to be a parent, instead of just assuming they will react the way you say. If you do tell them and they do nothing, I'd recommend you report this to your school guidance counselor or nurse. Their job as a parent is not being done well if they do nothing to help investigate what is causing your pain/s. For them to do nothing IS neglectful and IS reportable to the Dept of Children's Protective Services. Good Luck to you!