<human>: I'm attracted to my girlfriend physically and to the qualities she possesses, but I don't have the feeling of love that I've felt in previous relationships.  I told her this a few weeks ago, and she said that she has felt loving feelings for me, and we agreed to try to be more open and get to know each other on a deeper level.  Since then my feelings for her haven't changed much.  

Last night we talked about the future and she asked if I wanted to spend the rest of my life with her.  I said "Honestly, I do not know if I want to spend the rest of my life with you."  She immediately got up and drove home w/o saying a word.  She later apologized for leaving and admitted to being immature, but it still raised a red flag in my mind.   

I feel as though we are at different stages of the relationship, and that I'm waisting her time by continuing to be with her.  She is looking for a lifetime commitment, and I am trying to figure out if I can even love this young woman.  I'm afraid that if I let her go I won't be able to get her back.  Does any of this sound normal?  Am I being selfish in this relationship?

Condense the text into a few key points
<bot>: I'm attracted to my GF but don't love her, we're at different stages of the relationship, I'm confused.  Please help.