I used to suffer arachnophobia. I got over that by working at a pet store. I started by simply touching the tarantulas. I then progressed to picking them up, and allowing them to crawl on me. It started when I was a kid, me and 2 friends were exploring the back country out behind our cottage. As the day was ending we decided to walk through a field so we could get to a road that would get us back quicker. Half way through, one of my friends starts yelling and flailing about like mad. I looked on my friends back (we were walking in single file, but had turned back to see what was going on.) and he had at least a dozen huge spiders on him. By the time we got the the road, all of us were just crawling with spiders, young and old. From almost microscopic to HUGE.

(Like a 2 year old child's hand.)
Deep water. Not a fan. Not a fan at all.

I'm surprised to see so many of us mention this. I to am bothered by swimming in lakes/oceans. Wading in is one thing, dangling my feet down into the dark depths scares the pee out of me. I can trace it's origins right to the second this fear was forced upon me as a young kid. Though I know of 3 things total that lead to it, it was my brother freaking me out by pulling the plug on my air mattress and letting me sink. There was a log on the bottom of the lake right below me. He and my step father had gone on for years about the "Silver Lake monster". In my panic while sinking, my rational went out the window and that log was the "Silver Lake monster".

To this day I don't do lakes, oceans or seas. Well, short of floating on top in a boat.
I'm also claustrophobic. Kinda funny for a home body like myself. I'm find being in small spaces, as long as I know I can leave. Remove that option, panic, then freakout city sets in quick!
Though not a phobia, others have mentioned, and I to suffer from anxiety/panic attacks. It doesn't help with the aforementioned phobias that's for sure. Hell, they may be why I suffer them.
