Undiagnosed musician (violin/viola)

I am a college student at The University of West Florida majoring in music education and have been on the Dean's List every semester. In January of 2013, I went to gym to get a good workout in before the spring semester started. Afterwards, I began to experience muscle weakness, body twitching and shaking, rapid heart rate, fatigue, dizziness, and overall weakness in my body which was strange considering that I have always been an athlete (years of cross country, track, soccer, and weightlifting).  My life has never been the same since that day.  The symptoms changed and developed into spontaneous rapid heart rate all the way up to 160 at rest and feeling dizzy and nauseous especially at the smell of food.  I lost 20lbs the summer of 2013 because I was so nauseous and dizzy that I could not eat.  I often have hot flashes and feel like I will faint, have nervousness, body shaking and twitching for no reason, get very fatigued very quickly, see floaters, have a minor headache and dizziness all the time, stomach aches after every meal, loss of appetite, and have rapid heart-rate and palpitations often.
      I have taken every blood test possible at the hospital here and they have come up with no conclusive diagnosis.  Brain MRI was normal, chest x-ray showed minor scoliosis, had a normal stress test, and the only labs that came back unusual were elevated serotonin, cortisol, and histamines.

(UPDATE Jan 2015)
       Over time, my symptoms have changed. I saw a chiropractor for the first time in February of 2014 and he realized my cervical vertebrae were crooked (probably due to my violin and viola playing for the past 10 years with my head slightly tilted and upright posture).  He used a tool to move my vertebrae little by little, and after one movement, I had a hot flash and expected my heart rate to spike as it usually would, but instead I felt almost completely normal. My head felt very light and free, and my heart did not race. I left in tears because I felt so good. He continued to adjust my cervical vertebrae two days later at my next visit and I continued to feel great. I thought it was all over until 2 days later I had a panic-like attack for no reason while I was driving home from the mall and my heart was racing like crazy, I was dizzy and uncontrollably shaking in the lower half of my body. I knew that it was not completely over, but whatever he did got rid of some of my symptoms.
             I have had only two panic-like episodes (when I was at rest) since seeing the chiropractor for the first time.  My headaches are less frequent, my heart-rate does not spike at rest, and I have more of an appetite and gained 15lbs of the 20 that I lost over the past 2 years.
      My symptoms are now an elevated heart-rate and shortness of breath after any minor physical activity (walking up stairs or jogging to the car), less frequent palpitations, seeing floaters that make me dizzy, hot back of the neck, tension headaches in the back of the head, overall groggy and dizziness, and easily fatigued.
       I have also received acupuncture in the ear (which did not do much for me), continued seeing the chiropractor for my neck and back (which relieves pain from playing for long periods of time), talked to a psychiatrist (to make sure I wasn't crazy and having psychological problems) took a low-dose beta-blocker that did nothing for my heart-rate, and received osteopathic manipulative therapy (basically a very deep, pressure-point based massage) and it actually seemed to relieve a lot of the tension and pressure in my neck and shoulders.
      My life is certainly not back to normal, but it is on its way. I feel like I am very close to figuring out what is wrong with me, but the Naval Hospital doctors refuse to do a neck MRI to try to find the cause of my headaches, neck aches, floaters, and dizziness.  The only things that have helped me feel any temporary relief are the OMT and chiropractor services, therefore I'll continue to do those things. This money has helped me pay for the chiropractor visits since my insurance does not cover them. They have decided to try to put me on anti-depressants or beta-blockers to see if that helps my heart, but now I believe my heart is not as much the problem as a side-effect.  I believe that excessively playing my instrument has something to do with my symptoms and pain. I believe that if they looked, they would find something, but they have no intent on looking.  I gave up on trying to go to the Mayo Clinic because I know that the Naval Hospital will never allow it.  They have constatnly ignored and denied my requests for a referral. I am graduating in May and hoping to land a full-time job in the next 8 months where I will hopefully get insurance where I can pick my own doctor and find one who actually cares about their patients and believes them when they say they are in physical pain, and not just crazy.
     I would not have had these small improvements in my condition without the help of my friends and family and GoFundMe. I work multiple jobs while going to school full-time but it would never be enough to cover my medical expenses and just regular bills from everyday life.  Thank you all for your support. I could not have done this without you. The little relief I have gotten is such a blessing. My single mother is so thankful that I have found a resource that enables people to help me during these hard times when we cannot afford to do so. Bless you all.