Those feelings are unpleasant because they're meant to spur you to ask her out. You're probably already too late on the uptake but better late than never. You definitely don't want to end up as the guy sobbing while their "best friend" who's also their love interest fucks another guy and you can hear them going at it. If she can't handle your true feelings then she wasn't much of a friend to begin with, only an egomaniac who loves the attention you give her.