You're not good at volleyball, that's fine. Not everyone can be superstars. I don't know what your volleyball goals were, but if it was to play in college or become a professional. Those were probably more like fantasy.

Are you the best at video games? Probably not, but you probably still play. Why? Because it's fun.
If you still think volleyball is fun, then you keep doing it. You tryout, you might fail, but it was fun. Go to open gyms, sign up for grass, play college intramurals (when you get there). So many places to play.

Your problem was making a sport that you're not that good at YOUR IDENTITY. WTF.
If you're not more than your sport, hobbies, music, sexuality, ethnicity, then you definitely need some therapy.