<human>: My girlfriend and I have been together for ~4 years. We met freshman year of college and have been dating ever since. After undergrad, we went to the same graduate school. We moved in together in August, and although there was a bit of a learning curve to living together, I thought we were doing really well. Not sure if its relevant, but we moved across the country for grad school, so we don't have any good friends/family and we've relied pretty heavily on each other for emotional support.

A few months ago I started noticing that she was sometimes sad for no reason and would not tell me why. I assumed that she was missing her friends/family so I planned some day trips for us to take together, encouraged her to try and meet more people (go to parties, etc.), surprised her with flowers, etc. During this time, we also started having sex less and less.

A couple weeks ago we had a much more honest conversation and she told me that her feelings for me have changed and she's not sure if she loves me any more. She still cares for me, but she sees me as a friend, not a boyfriend. She said her feelings started changing in February and she doesn't know why. There's no specific event that caused the change. In the mean time I have been trying my hardest to make her happy and do things for her, but I can tell that she doesn't see me the same way she used to. It seems that she wants to be in love with me, but she just is not.

Any advice guys? This was the girl that I thought I would be spending the rest of my life with and its ripping me apart that she's drifting away. It seems like there is nothing I can do. I'm just watching my relationship fall apart in slow motion. I'm willing to try anything to go back to way things were, but I just don't know what to do.

Can you condense the text into a few key points?
<bot>: Girlfriend of 4 years says her feelings have changed and she doesn't love me anymore. She just sees me as a friend.