[Not sure if this goes in relationships or emotions]

I'm wondering now that I've been exploring my own past and issues and personality what emotion is defined as what.. Right now I'm wondering if I am just simply incapable because of my past or am I just afraid?

The reason why I'm wondering is.. I have this friend. Who has become more than a friend in the past 3 weeks. He's been my first kiss, and seems to really like me. He's very affectionate, very cute, nice, etc. I like him.. Well I think I do. I did, I know I did, last week I was so sure I did.. and then suddenly out of no where my feelings went away as soon as the friendship started getting more and more serious.. Well I don't think they went away but they were locked up and I find myself hiding more behind a wall than before..

I feel tense.. but at the same time comfortable. I feel comfortable sitting next to him, comfortable with him hugging me or any of that.. But when comes time to hug him back, or whatever I resist.. And to be honest.. It's not that I don't want to, because I do, but something in my head just says 'no' and I'll act impulsively on that. Basically, I'm comfortable with him being affectionate on me, but I'm uncomfortable showing any kind of emotion or affection back.

I've been like this my entire life.. With every friendship, with every relationship, I can take people needing me.. but I cannot invest myself in return and that apparently that makes me a "lousy" friend/girlfriend. I want to be able to relax but I feel unable. I want to be able to do whatever I feel but my brain wants me to stick to my bubble and not go around anyone else.

I don't understand it really and I'm going to hurt this boy unless I figure out what the hell is wrong with me and how to handle it.