Feeling let down

I mentioned that this weekend was a little dramatic. I have struggled with how exactly to post about this without it being a word-for-word recap and a really long story. So I'm gonna do my best.. I have mentioned my struggles with friendships before. Well, this weekend just confirmed what I already knew, but didn't want to admit... that I really am alone. People who I cared about (and still do, whether I like it or not) proved to me they don't care about me. And as much as I knew that, it still sucks. There's really no other way to put it... it sucks. These people, especially one in particular who I considered "my best friend", have been my friends for 3 years. I mentioned before I was the basketball manager my last 2 yrs of high school, and this allowed me to form amazing bonds with girls on the team.. or so I thought. I am the type of person that always wants to please. I put others needs before mine. I always pay for things, because it makes people happy; I offer to drive everywhere and use my gas, just so other people don't have to. I really go above and beyond for people in my life, because I care. And all I want is for them to care, too. I'm no therapist, but if I had to guess I would say it all boils down to my insecurities. I am insecure with myself, and as a result, I do whatever I can to get people to "like" me. Everyone in my life knows this person isn't good for me, even her own boyfriend has expressed his realization that she "doesn't appreciate me." And I know it's true. I have known for 3 years that she didn't care about me the way I did her. I always had the feeling that our friendship was based on what I can do for her, and her need for me. She always denied it, and I wanted so badly to believe her. Deep down, I knew. I'm not stupid. I just wanted to believe the best, not the worst. I made all kinds of excuses for her- she doesn't have a good relationship with her parents (they are crazy), she doesn't know how to be a good friend, she doesn't know how to have a functional relationship. At the end of the day, though, I was the one crying, not her. I knew... but it still sucks. It sucked to sit on the stairs in my own house this weekend, after a night of arguing with her because of her lack of respect for me, and listen to her talk about me behind my back and say some of the rudest, most hurtful things. And coming from someone who I care so much about, it hurt more than words can say. I am not dwelling. I am going to college in 2 weeks. I don't have to talk to her, or the other 2 friends I was with who were also horrible to me, but it hurts. And this is never how I envisioned spending the last 2 weeks before college.... I am hurt and I am upset. And I don't know what to do... I want to talk to her and find out if she meant the things that she said. But what is the point? For 3 years it has been constant up and down and it's never going to change. I will be ok. I know that. I will make new friends. I know that, too. But for now... it sucks.