Psychology shows that people are always going to enter into an interaction with a pre existing expectation or a Schema. The next person you know you see in the street is going to have an entirely different schema, and therefore an entirely different image of you. You really have no choice but to just be yourself, rather than trying to change to make everyone like you. Express your opinions because you know they matter. Say what you feel. Speak your truth. Try new things even if you think you're going to fail.