I can so relate to the introvert section of your post. By your scale, I'm probably 99-100% introvert. I shy away from any attention on myself and always divert. In your centre of attention at a party scenario, I'd be the guy hiding in the corner not talking to anyone.

Actually scrub that, I wouldn't actually be there. The thought of even being at a party scares me so much I probably wouldn't go (I missed a friends wedding cos I couldn't face being around all those people ).

I also read and re-read my posts, and then usually realise once I read it again after submitting it that I've still got it wrong!

It's really good that you're coming to this realisation about yourself. Maybe you could consider some counselling to see if you can come to terms with both sides of yourself. No-one should hate themselves or feel like a fraud. From what you've said, you're a good friend. The people who confide in you, trust you enough to share, so that shows they feel they have a good friend.