I Am Having Abnormal Sleep Issues For The Past Couple

I am having abnormal sleep issues for the past couple of months. I sleep very little or very restlessly at night, but during the day if I sit still, my head will literally fall over and I don't seem to be able to control it. If I sit still, especially if it is warm I fall asleep. (very embarrassing when I am in a meeting!) I am also having horrible ankle/foot swelling in spite of the fact that I drink large quantities of water consistently. My husband thinks I have apnea and says that I stop breathing during the night.