I feel hurt by my new boss.
What did they do that hurt you?
He said that my shoes aren't appropriate for the office.
You're being much too sensitive about what he said. You shouldn't react emotionally to comments like this.
Who are you to tell me that I'm overreacting?
I believe it's an overreaction because it's your boss's job to tell his employees what is appropriate in the workplace. When you work somewhere, you're going to have small conflicts like this and you need to be able to except them and move on, otherwise you'll be constantly overwhelmed by minutia.