Can I report a historical mental abuse by a teacher in the 70sWatch
Find out of he's alive and still teaching, if so report it to the school. I'm doubt anything will come of it, but you feel its something you need to do then do it. Talking to some kind of support group will probably achieve more for you mentally though.
You're not going to get any dramatic confrontation with them, even if they're alive/still teaching (v low chance)