Okay, first of all i'm 18 years old and a senior in high school. Me and this girl have known each other since the 7th grade and we've always been extremely close friends. Although we were friends, there was always this connection between us. But other complications (other relationships and timing) have and still prevent us from trying to be a couple. We've only recently tried to see if a relationship could work (about a month ago) although she has a boyfriend that she's been seeing for some time now. But things between us have been great. We talk on the phone for hours on end, we spend a lot of time together. We always tell each other how strongly we feel for each other and how much we appreciate one another. Now about a week ago, we were spending time together at my house. Things got heated and we ended up having sex. She was my first and we both enjoyed the time we spent. But since then, she doesn't call me as much as she normally does. Whenever i call her, she's either busy or sleepy. She says she'll call me back but she never gets back to it.

I don't know what's wrong though. I don't know if I've been lied to and possibly used to satisfy her lust. I don't know if she feels guilty for cheating on her boyfriend and doesn't want to see me anymore. I have absolutely no idea and it's been eating me up inside for the last week. All these things are constantly on my mind and I'm having a hard time focusing. It could possibly be because she was my first and i feel attached and want this relationship to mean more. Honestly, I'm just utterly confused.

Any advice on what to do or ideas on what's happening are welcome (please be truthful).