No words online are as good as any words spoken out loud
Had a quick look..... Better to just walk right up to her and tell her.
In all honesty I think its waaaaaaay better if you tell her face to face and speak from the heart on the spot. It may be difficult and online may be your only option but if the girl is worth it I think face to face is the best way. Good luck either way man. Letter was pretty long, I remember one I made when I was your age was like 4 lines long lol but nah its good.
It sounds nice, good luck:D