A Day of Tutoring

Should I have a coma in the middle of this sentence?
*
I am sorry I am later. It took me ten minutes to ignite my car.
*
Am I making P correctly?
*
Did you have an accident?When I was skiing, a tree got in front of me and hit me hard!
*
You called at the perfect time. I just walked into a door.
*
Please don't shoot so many people in my country.What?Please don't shoot people in my country very often.Could you say it really slowly?Police don't shoot people in my country very often.
*
I'm sorry, but I couldn't write my essay. My roommate had a toothache this morning.So you couldn't write your essay?Yes! She was swelling and decaying badly!
*What did you do this weekend?We went to a Karaoke bar.Did you sing?Yes. I was shy but I strongly did it.What did you sing?"You are the wind beneath my wigs."