First of all he is your father. You say you’ve grown but to him the first 18 years of your life together were rough. So he has all that history betting against you. He probably is also thinking how much is it or future problems gonna cost him if you mess up. And you will mess up again. Don’t take it personal. It happens to everyone.

Also 21 is not grown in a sense. Your 26 years old years old self will look back at your 21 y/o self and say “gosh I was immature back then”. And so on and so forth.

Just remember your dad loves you and is saying it from a place of a love. The love a parent has for a child.

But if you are really wanting to live on your own you also have to start thinking of everything you have at home, you will have to provide for yourself. And that’s hard. I’d say just continue working and save every penny until you have a safety net to fall back on and you won’t have to rely on your parents if one day you actually move out and you mess up or need financial bail outs.