I’m so so sorry your son didn’t have access to a more accommodating educational environment that helped him to thrive. It sounds like you and him both did your damndest to help him succeed as best he could, even when the cards were stacked against him and the game was rigged against people who work the way he does. It’s so hard not to walk away from an experience like that without blows to one’s self-esteem; it really can be traumatic and make motivation and focus worse. I hope so much that now that he’s out of it, he can work to find a context that plays to his strengths, and that he can find ways to feel affirmed in his value and ability.