It will only make a difference if you make a big deal about it. I am almost 23 and my boyfriend is not even 21, and we have never had any issues about our age because it doesn't matter. As far as a long distance relationship, those are really hard, I don't mean to get you down, but you both have to be very strong willed to make anything last. As long as you both are trying your hardest, you've got a pretty good shot. Good luck.