Critter phobias are pretty common. In fact, they're right up there with heights, public speaking and flying.
Which is worse for you--being in a room full of crawling spiders, a room full of slithering snakes or a room full of scampering rats?
Snakes: Ophidiophobia
Spiders: Arachnophobia
Rats: Musophobia
As someone who has worked with people with phobias for 20 years, I have to say that sometimes immersing yourself until you are desensitized is helpful. Just look at it this way. You begin flipping through a Playboy magazine and after a time, you need a Penthouse. A while later, you troll around online looking for the most hardcore porn you can find. It's not hard to get used to stimulation and need something stronger. Well, in the case of phobias, you can build up a tolerance.
So, what are some movies that might help you? Let's see...
Ophidiophobia: "Anaconda," "Snakes on Planes," "Python," "Raiders of the Lost Ark."
Arachnophobia: "Tarantula," "Arachnophobia," "Eight Legged Freaks," "Horrors of Spider Island."
Musophobia: "Ben," "Willard," "Food of the Gods."
Me? I grew up catching grass snakes and black snakes and playing with them. I'm not freaked by spiders. I think they're amazing creatures and I respect the hell out of them. True artisans! And, they seriously want nothing to do with us. Rats freak me out because they scamper so quickly and I remember seeing creepy movies where rats were gnawing on people in sewers and it's just super ick!