You don't have to worry about annoying me. I'm here to help. If a 14 year old girl liked me, and I had a girlfriend at the time, no I would not hate her or think that she is weird. I think that you should consider what you will do about the situation, though. He is four years older than you, and while normally that isn't a problem, at your age it is a big difference. He has a girlfriend, that is another problem. You shouldn't try to make any moves on a guy who's already taken. I can't make any more specific suggestions because I don't have enough information on the situation.
There is no easy way to get over someone. Though, not having them in the first place would make it easier. First, let me applaud your mature choice. It is very hard to give up something that you like. Now, I would suggest finding something to distract yourself. Something healthy, mind you, not anything like an eating binge or a rebound guy. Something more along the line of running, or reading, or writing. That would probably be the soundest course of action. It will take time, just as anything else does. But you will find other guys in your lifetime. You have a lot of time left. Just remember that you are a princess and deserve to be treated like one. Don't ever let a guy treat or make you feel otherwise.