Hi, Welcome to Healing Well.
First, no doctors are here that I am aware of, and no professional advice, it's more of people's own experiences and suggestions. It's important you continue to be seen by your doctor.
One thing I wonder about
is hyperventilation. Read some of the symptoms here, but please note, this seems to be a blog post. Yet these symptoms came to my mind after examining more professional sites. www.asthmacare.us/ac_blog/?p=188
Tension can cause hyperventilation, hyperventilation upsets the chemical balance of the blood, and peculiar symptoms can occur.
Blood tests and comprehensive blood tests may not be the same thing, be sure your doctor is looking closely at a variety of vitamins, minerals, electrolytes, thyroid levels, etc. in the blood.
I'd look at what you're eating, not eating, and the amount of rest you're getting as well. I'd avoid caffeine, energy drinks, etc., anything with excess amounts of vitamins, minerals, and caffeine. Also, be sure your doctor knows of any other medications you use, even over the counter or recreational. Eating balanced meals, slight supplementation of vitamins, and getting enough sleep may be helpful.
If the doctor feels you are physically in good shape, consider seeing an Endocrinologist. They specialize in more subtle issues with blood levels of various substances, you can have something in the normal range on a blood test but have it not be suitable for your health..I've seen articles on subclinical hypo and hyperthyroisism, and I'm sure the effect applies to other substances as well.
Hope this is of some help, try reading other forums here to see if anyone else experienced similar symptoms, particularly at a similar age.