I can only suspect that you experienced blame and shame as a kid and that you are still carrying the idea that you will be put down. Somehow, some way, your self-esteem took a beating. You may have unconsciously figured out that a way to avoid feeling terrible is to beat the accuser to the punch. You blame yourself before someone else can. That way, you are at least somewhat in control. It’s as if you are saying, “You can’t tell me anything I don’t know. I already know I’m at fault.”
But that’s just a guess. In order to really help you, I’d need to get to know you and to understand how your past influences your present. I could then offer you a more accurate explanation as well as some suggestions for how to deal with your perception that others judge you so negatively.
This is a hard way to live. I hope you will consider seeing a mental health counselor to help you. You are only in your twenties. You don’t have to live with this anxiety for the next 50 or so years. A counselor will help you understand the roots of your self-blame and will help you find ways to free yourself from constantly assuming the worst.
If you can’t get to a counselor right away, I urge you to look online for ways to create a more positive self-esteem. There are also some excellent workbooks available from online book sellers. Give yourself the gift of spending an hour a day working on yourself.
You need and deserve to have a more positive self-concept and a more friendly view of other people’s opinion of you.
I wish you well.