I understand how difficult this is for you. The suggestions from Victoria are great, especially managing blood sugar with nutrient dense foods. I would elongate the exhale to 6-8 counts and do this while lying down. In addition, resting with the knees about the heart (use a wedge or lots of pillows), getting 9-10 hours of sleep nightly, reading the Adrenal Fatigue book by James L Wilson, and getting acupuncture would be my suggestions.
To that I would add special breathing exercises that will rebalance the oxygen and CO2. If your resting pulse is rapid (>90) most of the time and you have difficulty holding your breath, then you may want to explore the Buteyko method. And if you wish to have a therapist teach you this method, Kathy Winslow in the Bay Area is an excellent resource.
I think that adrenal glandulars may be too strong at this time, given what you describe.