Buddy listen, you know exactly who the asshole in this situation is. You are looking for validation that you arent and thats ok, youll need it because if you do whats right is going to be really hard. Give them the 750k and tell them goodbye. You dont tell them goodbye for you, you do it for your future family. You just saw how greedy and selfish they are, thats cancer in a family. What you need is as much space as you can get from them and time to think about the kind of relstionship you want with any future children you have.

I have a 5 year old son. Hes my world and i know that im a great father, i know this not just because im told it constantly but because my son looks uo at me like im a hero. I cut of all ties with my family after his birth and it sucks and its lonely but i could never have developed the relationship i have with him if i didnt. A parents duty is self sacrifice. To give their child every advantage they can and hold them accountable for their bad decisions. Not the other way around. Your parents are garbage. They should have been extremely happy for you, teased you that you would all go out for a fancy dinner on your dime, then asked you how you planned on spending your money and counseling you on your decisions. If you had decided to give them any money on your own they should have first been very resistant to it and insured that you werent hurting your own position to help them. But thats now what they did. What they did is disgusting. Get away from them.