There likely isn’t any harm in sharing your story. The fact that Buddhism has helped you is a fact of your life (my story is similar). Usually, you can sense when it’s appropriate to divulge such details, like a hint of curiosity to know more. When those moments arise for me, I briefly mention the benefits that meditation has had—without referring to “Buddhism.” And if they’d like to know more beyond that, I’ll share it.
As far as volunteering information to people, I take a similar approach. If I know someone who’s struggling with stress, burdened by their emotions or duties, I’ll recommend some simple mindfulness or breath meditation—again without referring to “Buddhism.” And if they’d like to know more beyond that, I’ll share it.