Kjs.
Let him stomp.
Not your problem.
Next day, if he's mouthy, tell him again. Calmly. "You may not speak to me like that."
If he asks for something later, tell him again. Calmly. "No, you did not talk to me nicely this morning. Try again tomorrow."
If you continually give in to him to avoid feeling guilty, he will keep doing what he is doing. He sees you as a pushover, and will treat you as such.
If you want respect, demand it.
(yep. still going to ER. Waiting for mom to pick me up.)