Girl from summer reappeared

The girl from summer reappeared then disappeared. I feel sad a bit and hurt. I called her on her b'day I guess we had bday sex. We met at the cupcake store I out a candle on it sang Happy bday she made a wish we had some drinks I got wasted and then she came back to my place.

I feel inadequate around her. Not to get too graphic but I just feel my performance lacks all around and she is taller than me by like 4 inches. I'm scared to tell her about my lack of sexual experience but I do feel that would maybe help. The next day she told me she's not looking for a bf and or even sex and that things just happened. I agreed with her and said that Its all good. I thought that this was the best way for me to not get hurt like I got in the summer but now I'm hurt a bit bc we haven't communicated for pretty much since the beginning of the week.

I need to concentrate on studying so I just know that's it's a bad idea to chase her bc my energy needs to be spent on other things. At the same time the angst from not hearing from her is building. I don't think she's doing anything to hurt me on purpose. I just want to know wherr her heads at I supposed. Or if that was just break up sex we had.