So just because someone has it worse you have to enjoy your job? Doesn't work like that.
What the OP realised is that money is no good if chasing it wrecks your time. Is he lucky to be able to choose another way? Yes, but that doesn't make his decision any less valid.
Sure he has his reasons but it's most because he is making a decision that he believes is the right to do, not because his employer did something wrong.
I am in the exact same situation as him (without the equity large enough to cover my mortgage), but I recognize my last employer was actually good to me, my unhappiness was not their fault.
Also typical in the first world: ignoring and belittling mental problems like they are inferior to physical ones. Both suck but just in different ways.
What the OP realised is that money is no good if chasing it wrecks your time. Is he lucky to be able to choose another way? Yes, but that doesn't make his decision any less valid.