childhood fears

when does childhood fear become something more? My son has always been reserved and never liked things he couldn't control but the older he gets the worse it seems to be getting and I'm starting to feel bad because he's missing out on things that should be fun for him. He's 4 1/2 he's scared of the dark, animals, rides, characters dressed up in costumes, water, and I'm sure there's some I'm forgetting. So he's never rode a swing at the park or ride at an amusement park, he's never petted a dog/cat, he refuses to go anywhere near Santa or anthing like that, he will not get in the water far enough to learn to swim and even has to wear goggles in the bath tub and freaks if water gets on his face. We took him to the circus thinking it would be fun but he refused to even step foot in the arena for 15 minutes and we had to bribe him with cotton candy. I know most of these things are things kids are scared of but is it normal for him to be fearful of everything? When does it become a problem? Our life is very secure and his life is stable and I really can't think of any "reason" for him to be so fearful. My DD is 2 1/2 and she's the exact opposite and has no fear of anything, lol! I just want him to have fun and be a happy kid...

I would get him checked out for sensory disorder issues. I'm no doctor by any means and its normal for kids to have fears and such but some of those sound like sensory issues.
http://www.essortment.com/symptoms-sensory-disorders-children-57219.html

Quoting ----&&:" I would get him checked out for sensory disorder issues. I'm no doctor by any means and its normal for ... [snip!] ... and such but some of those sound like sensory issues. http://www.essortment.com/symptoms-sensory-disorders-children-57219.html"

I don't think it's a sensory issue I think it's more of a control issue, maybe OCD or an anxiety issue. He's very social and as long as he feels that he's in control he's fine. Like he'll drive his car around the yard because he can control it but doesn't want to try the rides because he asked me "what happens if I want to get off" so he knows that someone else is controlling it. I think it's the same with animals, he knows that they are really the ones controlling them and that even their owners can't stop them from barking at him. He has no behavior issues and is ahead developmentally and likes to play with sand, play-doh, loves dancing to loud music, and sitting for story time at the library, and never had any of these issues when he was a baby, they all seemed to pop up around age 2. That's also when I had my DD, so I just wonder if he maybe has an anxiety disorder or if he just has the normal fears that kids have