23 and Immature.

I'm 23 yrs old and I can honestly say I make myself look like a fool and a clown. I'm immature for my age and I need to grow up because I make myself look stupid by telling my relationship issues, life issues, and any issues to people who will listen. My recent ex said I brought the worst out in him by going to others about our relationship and not keeping things private. That I make myself into a joke. I'm too trusting and need to stop telling my and other ppls buisness. What can I do to be a lot more private and to mature a lot more? Please don't be harsh I'm admitting my mistakes. I just need advice.