Do relationships with big age difference usually work out?

I'm 20, and he's 28. And I'm rather childlike and immature in a lot of ways, while he is very reserved (never swears, always polite). Because of this difference, we argue sometimes. I am always the one that starts it... for some stupid reason. At first I didn't think much of our age difference, we've been loving each other deeply for several months now. This is also a long distance relationship. We see each other for a week or so, every 3 or 4 months. Otherwise we chat online almost every day. But recently I've been thinking about it alot... to the point where I'm thinking maybe we're not for each other. When I think about how, when he was in college, I was still in middle school, learning how to spell. That, to me, feels really off. Sometimes I look at guys my age, and I feel like I could find more things in common with them. But I feel horrible about feeling this way, because he has no idea that I'm slowly falling out of love for this reason. I know he has the right to know, but I just can't bring myself to talk to him about it... so... do you think a relationship like this has a chance?