Straightforward is the best approach, just face your fear and tell her. She may not say it back but she will be flattered that you said it. After that act normal and if she loves you back she will let you know eventually.
Say no to what? You may be attracted or infatuated, but "love " is only possible in an actual relationship. At this point, she is your crush. All she can do is say yes or no. Go for it! If girls don't like you, there is a reason and you know what it is. Tone it down.