Sometimes, when I wake up or stretch during the day, I get lightheaded and then I can’t feel most things. My eyes stay open, then black closes in and I can’t see or feel myself breathe for about 3 seconds, then it clears up, and I gasp for air. At one time I did pass out from such things, of which I fell on my computer chair, and woke up a few seconds later with an “mysterious” pain on my back because I had fallen on the chair. I take a generic form of Concerta for my ADHD and take Benadryl at night for my horrible allergies. Anyone know what’s happening? And why? Thanks, in advance.