Don't deny it. Honesty is the best policy here. It's okay for your friend to know you like her! She'll probably be flattered to know, and it shouldn't ruin your friendship (dating and then going through a horrible break up will ruin your friendship, but not just sharing your feelings).
Make yourself happy and don't focus on making your lover happy. Your lover will be happy to see you happy. Allow them to make them-self happy so you can be happy seeing them happy. If they are not happy seeing you happy, or you are not happy seeing them happy, then it's time to leave each other and find that happiness elsewhere. Life is too short to bother with any other emotion for longer than absolutely necessary.
-Shela Aetherius