Well, first thing I can think of is, some parents will always think they are right (I am the adult, you are the child).
I had that issue when I was growing up, my father made it very clear to me that I am what I am, and no amount of wishing otherwise will change it. But, he also told me "once your 18 you can do what ever you damn well please".
Sorry if I turned this into a "Helping Dependent / Child Understand".
You could also tell your father that these are the steps you will be taking once you are on your own, but would like to start them earlier. Try to make it sound a little more on his terms.
Might just have to bite the bullet on this one and tough it out for a few more years.