I want to be happy, I want to be happy, I WANT TO BE HAPPY!!!!

Why is it so hard to be happy. Initially, I thought having a girlfriend I'll be more happy. NO! I am NOT. Not at all. Being single, I am not happy at all either, because I am lonely. Having a girlfriend life should be better, but I'm wrong. TOTALLY WRONG. What should I do, I just want to be happy... just want to be happy...