Don't overshare things that could hurt your character. You never know who will hear. Imagine whatever you say showing up on a billboard... would it be embarrassing to see it up there?
Before speaking your mind, apply some quick filters to prevent getting into trouble. Ask yourself, "Would I be comfortable hearing this if someone said it to me?" and "Is there a better time, place, or way to express this?"
Have someone filter your speech
To avoid getting into trouble with your words, consider using a friend as a "speech filter". Find a trusted person who can provide honesty and support, and share with them what you plan to say or type.