<human>: Give me a shortened version of the text

I have been dating my girlfriend for 3.5 years now, and its been the best relationship I could ever ask for. The past 8 months I have been away at college, and although we were worried, we got through it fine even though I didn't get home much. However, about 5 weeks after I came home things started to feel different, she just didn't seem as excited about anything together as she used to.

After confronting her about it multiple times she finally caved and said she's been struggling and feeling distant. She said she feels like there is something missing but she doesn't know what. She said she grew more independent while I was away, and that with her graduating she was worried about missing time with her friends. She said she wanted to stay together, so I had no problem with backing off. We started spending much less time together, while she was often out with her friends. 

I thought this would fix the problem, but it didn't. We ended up getting in our first fight ever, and I offered to split while we were still on good terms, but she insisted she still loved me and wanted to keep trying.

Now we've fought three times in three nights, and although we always apologized and stayed civil, there's no sign of improvement. Her prom is next week and I'm terrified something could happen to set her off again, because I would hate myself if I was part of what ruined her big night.

I love her as much as I always have, but she hasn't been herself the past few weeks. We were always the couple that everyone said would last, and I want to, but I can tell her head isn't in it anymore.

She still says she wants to try, but she doesn't even know why she feels the way she does now. Does anyone have experience with whats the best way to move forward with this? I know we are young, but I cant emphasize enough how great the past few years were.
<bot>: Girlfriend of 3.5 years feels different about our relationship suddenly. Says she wants to fix us, as do I. Whats the best way to move forward?