I need advice on how to confront a person I like and how to get their attention?

I have liked this person ever since the beginning of my fresh year in high, and i dont know what to do… I am totally lost, and get REALLY shy when around her… I can’t be myself when talking to her, and start stuttering and my brain basically malfunctions… I also can’t get her to be alone… She has this crowd of guys and girls always around her and I can’t even talk to her sometimes. I feel like I’ve failed and want to bring my hopes back up to become brave and ask her before it’s too late… I’m planning to ask on Valentines Day, while on the mountain of our ski trip… HELP! Thanks