NTA but I don’t respect how you’ve gone about things at all. That said, I share my finances with my wife and if either of us won the lottery neither of us would ever in a million years think “I won” instead of “we won”.

Your money, spend it how you want, but I wouldn’t want you for a partner.

Also, your messaging on Dartmouth I think is way off to your kid. You sound like someone who never did university yourself and have the “it’s all a waste of money” bias that you secretly want to see your kids suffer for. I’ve seen a lot of those types of parents who grow up and regret that attitude when they’re alone in a nursing home.

But it’s your life, do what you want and who cares what Reddit thinks.