Most Helpful Girl
Well I'm 23 and very single, so I think you're okay :P
You're not old, you're not dried up, you're actually quite young. I playfully use the term "baby adult." Now, as a baby adult you are entering a time in your life with many transitions that can range from last years of college, graduating, jobs, internships, etc. All of these things are about fulfilling you as an individual.
To be single and happy? Look for things that make you happy. What makes you just awesome? What enlivens you? That is where you can allow yourself to grow even more as an individual, toward your future goals. And as you continue to grow and be involved in things you love, eventually you'll cross paths with someone who also is headed in the same direction, and things will just click.
So first, you need to allow yourself to move toward the path toward your growth. The goal isn't a significant other, the goal is for you to keep growing into the awesome, amazing you, and along the way, find someone who encourages you to grow toward that self.
Also, be gentle on yourself :)1THIS IS NOT RELEVANT ANYMORE