SUBREDDIT: r/relationships
TITLE: I [18M] love my girlfriend [18F] of 2.5 years, but I can't see us being together in the long term.
POST: Hey guys, I'm a first year in college right now and I've been dating my girlfriend for almost 2 and a half years now. Before my girlfriend and I started going out, we were pretty much best friends. Although we didn't have a lot of things in common, it was easy for us to talk and laugh with one another which was great. Throughout these years I've known her, I'm always really comfortable around her and would tell her anything. 

Recently we got into an argument and we realized how much we were different from one another. Throughout our relationship, there were petty differences such as food and music, but after that argument, I realized it was much more than that. Our values are different. After the talk, she dropped the bomb of "do you see us being together in the long run?" and I said yes and that was the end of that night around 2 weeks ago. 

After that night, everything has been normal. We still talk a lot and text a lot. But that question she asked that night has been in the back of my mind every single day because I'm not sure if "yes" was exactly the right answer. I'm afraid that if I end things with her, I'm not only just going to lose my girlfriend, I'm going to be losing my best friend as well. She has given me so much in this relationship and has really changed my life for the better. Not to mention that she was also my first kiss, first girlfriend, and a first for many other things if you know what I mean ;) 

So yeah, I don't exactly know what to do in this situation. Do I love her? Yes, I do but I don't know... I have the feeling that she loves me A LOT more than I love her.  Is this just some "phase" I'm going through because we've been going out for so long? Is it because I'm in college and I'm surrounded by so many new people? I don't know... please give me some advice and help me out here.
TL;DR: 
Realized my longterm girlfriend and I have a lot of differences and I'm not sure I see myself being with her in the long-long-run.