Assuming people do not like me

I (25f) started a master of social work placement in September and I find that I have repeated patterns. I start at a new place (whether that is a new school, job, placement) and I just assume people do not like me. Because of this, I come off as very quiet and somewhat awkward. I am so worried that people do not like me and I'd rather be quiet than be judged for my real personality. Once I stay somewhere for a few weeks or even months, I start to reveal my true personality and slowly get comfortable with people. I am also scared to make mistakes for fear of being incompetent or viewed negatively.

How can I reframe my thinking? I don't understand why I have always thought this way.