feeling twisted and possessive

I wasn't sure what tab in the forum I should place this in... but I guess this would be an emotional problem.

I've never been social in school, only recently have I been able to make friends and be comfortable around them without being myself. I am 16 so I guess this could be a misunderstanding, but I am at a loss so this is why this post is here.

In grade school I've been the outcast. While everyone in school had that one person that they would do everything together, I was the one person who did not and would be placed in as a third wheel in a group. In the seventh grade I made my own social life in an mmorpg for three years. I have been fine since the game, it didn't matter to me if I hadn't a friend in school as long as I did in game. I made a very good friend, but this relationship was odd, one I felt comfortable in. We never asked any personal questions outside of the game, to this day I do not even know this person's name, but she was a guardian to me, and a daughter to her. I have felt so possessive of this person whenever others came close, even if it was just a few minutes of her time, I was overcome by jealousy. I felt insecure in our friendship, she meant the world to me. I wanted to give her my everything, when I know I didn't mean that much to her. Is it wrong to feel like this? I feel twisted...

I've known a girl since the 5th grade, she is currently in my high school and in one of my classes. While i was an outcast in grade school, I had always hoped we could be friends. She was very good at art, and I was decent at it. We were known as the artists in our grade school, and from there I had always wished for her to notice me. She was the popular kid, a friend to all but never quite with a friend herself. I always found her different. I found myself thinking about her a lot, an unhealthy amount. When I got my game I forgot about her, but without my game I continue to think about her. She has always been different from the others in my eyes, her thoughts are very philosophical, more advanced than others. She has always been very attractive to me, and I know that many others have seen this, as they ask her out. I watch her go from one relationship to the next, never caring but always wishing for her to be a friend.

In the classroom, we sit on opposite sides of the room. My eyes wander throughout the classroom but I always end up looking at her. We became close when she broke up with her boyfriend, one she was with for three years. Although she had so many friends, she had no real friends there to comfort her, and so I did. We spent two months together, and it was the best. We related very well and she recovered slowly. Once she recovered she returned to her old friends, and left me. It hurt and I miss her, and now I am currently trying to spend more time with her. I find this infatuation unhealthy, my feelings feel twisted and wrong, I just need to know if it is wrong, and if I could rectify some wrongs.

I've always looked at her as a friend, and sometimes I look further than a friend, but I see our differences and I am fine with being just friends. I am just curious about why I feel very twisted. I give these two important people in my lives my best, anything I have that they want I will give. I give them my all, knowing they never would do the same, hoping that one day... they would do the same. I don't know what was it about them that makes me attracted to them, but I do know this feeling doesn't seem quite right.

Is this just some stupid teen infatuation? Or am I messed up in a way? Please help me to understand.

I'm sorry for such a long post, this is the first time I've tried asking others about my problem so please excuse. I think there is more than enough/too many details but if more is needed to answer my questions, I will do so upon request. Thank you for your time.