Whenever I start moving around, I get suddenly tired, lightheaded, hot, somewhat nauseated, and start belching. Once I sit down, I seem to feel my heart beating heavily near my ears. I have been diagnosed with anemia in the past (on B12) and recently with sleep apnea (on CPAP). I am not sleeping well lately. I start one project and begin another one all over the house. This really concerns me. I have an appointment with my primary MD next week. What should I do?