Do you see others sharing their lives and you don’t like them? Maybe they seem self-involved or obnoxious and you don’t want to be like them? Whose lives do you follow? What makes them different? Why do you follow them? It’s obviously because you respect a certain aspect of who they are. If you shared more of your life, could you be more like them instead?
Do you have useful things to share? Would people benefit from the lessons you learn? What’s stopping you? Is it ego? Do you doubt that you might be criticized and therefore you don’t want to be disagreed with? If there are people that would benefit from what you could share, then why does the possibility of a disagreement matter?
Absolutely everything you learn in life is a lesson that someone else is yet to learn. Publicly sharing an experience that you’ve had will not be useful for everyone, but as long as you can help one person with a lesson to learn, shouldn’t you get over yourself and share it?