Are you happy?

"are you happy?" is such a difficult question. I laugh at jokes, I go out and have a lot of fun. My life isn't as bad as it could be. And I don't have terrible problems, it could really be worse. But then, one night at 3am when I'm alone and still awake lying in bed, thinking about life, I find myself crying my heart out, suddenly convinced that no one likes me or nobody will ever like me. I feel horrible and I question everything I had. And I don't know if I was ever happy at all.