<human>: I have had a few girlfriends in the past but they never lasted longer than a few months. My most recent girlfriend and I dated for almost 2 years. 

I broke up with her two days ago. I did it because I wasn't sure if I could spend the rest of my life with her and felt like I was wasting her time and leading her on. 

I love this girl. She is amazing. I just didn't see it working out in the long run. I am completely torn apart. The sound of her crying and watching her heart break right in front of me was one of the most painful things I've had to do. 

I want to text her and ask how she is doing. I want to talk about what happened as emotions were running high when I ended it. I feel horrible. I'm lost. I want to hold her and tell her it will be okay. She wanted to spend the rest of her life with me. Get a dog, have a house, get married, and have a family. I wanted it to work.  She is an amazing person and the most beautiful girl in the world. 

Should I try to contact her? Wait a while and let the waters calm? Leave her alone? I miss her.

Can you condense the text into a few key points?
<bot>: Broke up with my first serious girlfriend of almost two years because I couldn't see myself spending the rest of my life with her. I am totally devastated and need any kind of advice.