College apps, letter of rec. please help?

Honestly, this is not the best idea because schools see high school as ages ago and they are interested in what you have been doing the last couple of years as a COLLEGE student, not a high schooler. Having said that, one is better than nothing and you can always send it and see what happens, but if I were you, I would start talking to my professors now by asking for rec. letters. Since they don't know you well, they might warn you that they cannot write an excellent letter, but it might be better than turning in an old, high school letter.