Real Life Problems

Sometimes do u ever wish you could go back and say something different. As an example, u were in a argument but then u start to think maybe i should have said this or this. I overthink alot of situations but i think its normal. Sometimes when im in public i think people are staring at me and judging me. This usually causes me not to go out in public as often. But when i do go out i feel like the people that are passing me are eyeing me and judging me on what i wear. Its almost as if my own brain is starting to create these scenarios where i'm being bullied by these people i don't even know. so am i crazy? Is this normal?