Stop right there. This is where I interject, and tell you to get it together! You don't need a boyfriend/girlfriend to make your Valentine's Day one to remember! Who cares if you don't have a romantic dinner date with your one true love? So what if you don't get a clump of thorny flowers that are going to die eventually anyway? You don't need a significant other to validate yourself.
I like to try to make Valentine's Day about helping other people, doing nice things for my friends, and occasionally leaving paper hearts in all the neighbors' mailboxes. If you haven't already, make your friends and family members Valentines. Put some effort into them--they might not be expecting them, and it's always nice to get a friendly card. Doing things for other people can have the funny effect of making you just a little happier.
Valentine's Day is this Saturday. Don't spend it moping, mooning over that one person's Facebook profile, or drowning yourself in tears. Take advantage of this day of love--because it's about more than just one kind of love. Take a friend downtown for a hot chocolate. Have brunch. Watch a movie with a sibling. Do something you are passionate about. Remember, your happiness is your choice.