I think I know a lot how you feel. Especially in that feeling, that you'd NEVER want someone irl to know about the problems you're having.
Afraid of how they'd react and maybe even worse how they'd treat you... how it might change in an odd way 'who you are' because of what you think.
I'm not saying that all people will understand, or they'll even say the right things to help you. It's ok if you're too afraid to tell anyone, I'm REALLY glad you're here so you can talk about this.
If you can get the courage up to talk to someone, it would probably be a good thing, so keep trying. Even if the person can't understand completely, you never know really. They could have had similar experiences and not told you for the same reasons you don't tell them, they might have NO CLUE what it's like but still care for you, and try to help you. And it's better to have someone to talk to you and maybe to hold you.

I'm kinda the happy all the time person- you can come to me and spill all your problems-happy- person to everyone irl. And I don't really want to change that either. It shouldn't change who you are just because you tell someone that sometimes you feel that way =D

is there perhaps ONE person you're more likely to tell than others?

*hugs* good luck and keep posting ok? oh and pm anytime ^_^