Sudden dramatic hair loss is usually partial and temporary. The technical term is telogen effluvium, referring to the shedding (effluvium) of hairs in the resting (telogen) stage. Normally 10% of scalp hairs are resting, but acute shocks to the system can increase the proportion to 30-40%. These include childbirth, high fever, sudden weight loss, etc. Three-four months later, lots of hair falls out. This continues for a few months, before the body's normal rhythm reasserts itself. This no doubt is what your dermatologist was referring to.
In other words, wait a while. Treat your hair normally and don't fret about the fall-it's likely that all or most will grow back. You will in all likelihood, in other words, never look like me!
Best.
Dr. Rockoff