Eyebrows keep falling out. Does this mean the root of my eyebrow is out? Will it ever grow back? (photos)

The white stuff at the end of the hair is most likely a waxy substance produced by an oil gland. This is normal.  It does not mean you are losing hair.

you need to see a hair loss specialist to find out the cause of the loss of hair in your eyebrow. Once the cause is established, then the proper treatment can be recommended. 

You need to see an expert doctor who can examine your eyebrows and determine why this is happening to you. By just showing a single hair, it really does not help make a diagnosis.