Has anyone forgotten chunks of time while having a panic attack?

Panic attack is a symptom of B vitamin deficiency. There are 13 to 17 B vitamins, depending on who does the counting, and they are not well studied. Most of them can substitute for each other, increasing the difficulty of knowing anything for sure. B vitamins regulate various energy exchanges in the body, and symptoms of deficiency are mostly psychological. Fortunately it is cheap and easy to test: get nutritional yeast powder and/or B-100 pills. Vitamin B2 is a water soluble dye that turns urine bright yellow. When the color fades, it's time for another dose. Read some books about nutrition so you know how to eat right.