Does this make me a bad friend?

My friends are very open and honest about their personal their. We've had many conversations about their relationship issues, financial issues, mental health, etc. I am the complete opposite. I don't like talking about myself at all. I like to keep my private life private and it seems as though that's a problem for them. Am I wrong?Am I obligated to share the details of my personal life just because they're so open about theirs?