Complex sentence: Mulder tells Scully that he watched Deep Throat's funeral using binoculars from one-thousand feet away, and is so depressed that he is now even wondering if the "little green men" he's seen are all in his mind.
Split into simpler sentences: Mulder tells Scully that he watched Deep Throat's funeral using binoculars from 1,000 feet away. Mulder, obviously depressed is now even wondering if the "little green men" he's seen are all in his mind.