I believe the problem with him, as you mentioned, is his
divorced family. You said that you and him have always been sitting
together, in class and all. I think the reason for him getting all
worked up and rude that day may have been caused by family woes.
Someone who comes from a broken family often has no one to confide
in and the stress + worries starts to accumulate within him often
resulting in severe depression that can cause sudden ‘bursts of
anger’ which you, unfortunately, had to endure. But still, you
should forgive him, knowing his plight and situation at home. He
probably had moodswings that day and so took out his frustration on
you as both of you sat together in class.