Hahaha!! I had a ball going through your comment. Quite surprisingly, i'm not terrified one bit from spiders. Just three days ago, i got bit by one on the neck and i walked it off like a champion, while brushing the spider aside with my hand alone.
I recommend watching an old movie "Eight legged Freaks". Maybe it might serve as mental training to fend off the fear of spiders. Or since fear is irrational, it could either escalate it further. But you won't know until after you've watched the movie.
Australia is definitely not the place to be, if you got the fear of creepy crawlies. Oh! They got giant snakes too. Wouldn't really want to face off against those.
You know what's worse than moths? Flying cockroaches, I had the same experience as you in the bathroom as a child, except it was a flying cockroach. The unpredictable nature of the flying insect is nerve wrecking. Will they fly inside your mouth? Crash land in your ear, or fly all the way inside your head? Frightful!
Spiders! Totally irrational and silly. Also, I think, cultural. My impression is that British people (who live in a country with no truly dangerous or even big spiders) are very often terrified of them, while Australians (who live in a country with literally aggressive spiders who choose to attack people) are almost never scared of spiders and think we are idiots. I am getting less scared of them these days, but I can't imagine being the kind of person who can just let them sit on the wall watching and planning my demise!
Oh, and moths! The haphazard style with which they fly freaks me out. They bounce all over the place and it is just a matter of time before they bounce on you. This fear has been with me since very early childhood, when I apparently ran out of the bathroom one day and informed my mother that "There's a mop in the toilet!!".