As a teacher I can't quite comprehend why he would say 'you're suck' instead of 'your skills are profoundly deficient,' unless he was trying to 'communicate with the young folk by using their lingo.' But for sure, not planning the work, combined with putting off studying till the last moment is pretty much the road to failure.
My father used to tell me (and god how I hated it) something over and over until it was so ingrained in my head that I had to do the same with my kids, until they hated it to. It was:
Plan the work and work the plan, because failing to plan is planning to fail.
So, I'd at least try to talk with the person, find out if you can retake the quizzes (I never allowed it, but many do), or do extra work (ditto) and tell him that if he has something to say to you, he should talk to you and not your brother.
And plan the work from now on, and part of that planning is to have ongoing preparation for the test so you're not doing it at the last minute.
And planning and all that does not take care of all the problems. Stuff still happens, things come up and all that - but it does take care of 95% of the problems, and it's sure a hella lot easier to work 5% problems rather than 100% problems.
