Why do I have demodex linfestation in my hair in my nosterls /eyelashes private parts hair not growing back the way it use to and falling out easy, ?

Mites. They are more commont than you think. Spread from person to person. Live in hair follicles, eyelash eyebrow and nostrils . If problematic see ophthalmologist for tea tree oil and Pilocarpine . Together I have had very good success.
Pubic Lice. Pubic lice, also called crabs, are usually found in the pubic area. But they may also be found on facial hair, on eyelashes, on eyebrows, in the armpits, on chest hair, and, rarely, on the scalp.