What horror movie is this?

o.k., it's a movie with teens from a high school, normal high school, then this alien type thing infects all of them, like alien form alien vs predator, but its not that movie, and the only way to keep the aliens away is if they snort this drug and at the end, the football team and coach try to get a player and the player trys to hide in a bunch of school buses, and at the end is this final fight with a nerd and a hot *** chick and it shows her but her shadow is like, a huge *** ******* alien with like million tentacles, the movie is made like in 1990's, 1996 to 1998 for a guestimation, ty