I'm 18 and a freshman in college. My girlfriend is 16 and a junior in high school. We started dating when I was a senior and she was a sophomore and have been close since I was a junior and she was a freshman.
I love her very much. She is easily the best influence in my life. She's the reason I didn't take up drug dealing back when my shit was sort of spiraling out of control. She pulled me (mostly) out of the abyss into which I had so whole-heartedly leaped.
On the other side of the coin, since being with me, her depression has been a lot lessened. She is no longer bulimic as her self-esteem is much higher. Whereas her previous boyfriends had a tendency to force a lot of things on her, our first time was her idea. It wasn't hers, but it was my first time in general to be honest.
Anyway, the point is that unless the age difference is enough for there to be legitimate coercion involved then it is really not a problem. I've been with my girlfriend a little under a year, but I simply can't imagine a life without her in it. She keeps me sane and makes me really happy. As far as she tells me, I do the same for her.