My eggdonor married such an idiot, so I can relate.
>I didn't raise you to be this useless!
What did he raise you to be, though? I believe his anger came from projecting his own incompetence in teaching at you. Some people are so bad at dealing with their own ignorance that they need to blame the oh so almighty school.
>think about how useless I am
With all the respect you deserve and with no intended blame, you're just imagining this. There is actually not much happening in his head in this moment, except an enormous effort to suppress any feeling of responsibility for the situation.