Well my Father has definitely said “If you want something done right, do it yourself”, but that is not his favorite expression. His favorite expression is “Make us both happy, do it my way”.
The stages of grief can take months or years to work through. My Father could take that long to change (assuming he does)? Wonderful.
Since you were born, he’s thought of you as someone who, with any luck, will have the good sense to grow up to be just like him. That dream is going to die hard. The good news is that he never has to agree with you in order to accept that you are a man who makes his own decisions. The bad news is that unless he has a life-changing epiphany of some magnitude, that realization that you are not him is going to grieve him for a long time.
Think of a lab mouse who is used to pushing a bar and getting a peanut. Then one day, no peanut. Hit, hit, hit, hit. If the mouse starts getting a peanut every once in awhile, it will actually hit the bar more. It learns that it can still get what it wants, just by hitting the bar enough times. Now, make that lab mouse into your dad. Your job is to teach your dad to predict accurately when hitting the bar more than once is going to do no good. Your goal is to give him cues about when you can be swayed and when you can’t. Don’t bite off more than you can chew, or you’ll have someone you know to be a very very persistent mouse dogging you to give him what he wants until he drives you nuts and succeeds.
What you want first of all, then, is to choose your battles very carefully, especially since at this point bluntly striking out on your own is probably a version of cutting off your nose to spite your face. Instead, bide your time, and don’t cross him without good reason. Where he is in control and you can’t change that, be willing to admit it. After all: What makes him respect someone’s opinion? Well, when they agree with him, of course. So when you disagree with him, you do it this way: I agree with you about a, and you are right about b; we just disagree on how to get there or we only disagree on c. What you avoid is personal comments (even if true) such as: You just want to run my life, you treat me like I’m five, etc. No, you have to show that, by and large, you respect his opinion and think he wants what is best for you. IOW: Do not get in ego battles!! Those will work out badly for everyone, but mostly you. (The great irony, of course, is that I would give him very similar advice. Ah well, he is not asking, and you are. It is a good thing that it only takes one sensible person to keep most battles civilized.)
This gets him used to the idea that you don’t disagree with him just in order to show him that you’re your own man. You only disagree when necessary. Your mother will also be in the position of hearing you and thinking: Hey, Brad isn’t trying to be rebellious. He agrees with his father on nearly everything. He’s a sensible kid; he just has this one thing that his father won’t back down on. He’s trying to get along; he just doesn’t agree about everything.* I know what that feels like, and I feel for him.*
You don’t want him to get used to the idea that it means nothing when you draw a line in the sand, that you’re just difficult for the sake of being difficult. You want to give him the idea that when you draw a line in the sand, you do it because you have to, and when you do it, you mean it. When you have the decision, you calmly and firmly stick to your guns. You don’t want to give him the pay-off of drama and hand-waving and all of that. This kind of thing encourages him to think you’re still five years old. If he drives you to tears of frustration, hold the back until you can indulge in private. I will guarantee he will not see them as a sign of how passionate you are. (Not fair, but we are interested in getting through this with the biggest piece left intact, not re-wiring your dad’s brain. Keep your eye on the ball!)
You might also ask your mother how she copes when she wants something and your dad will not give in. Trust me, there is something. If you show yourself as someone who wants to both get along with your dad and have some semblance of autonomy about something, I think she’ll relate, even if she doesn’t have much but sympathy to offer. If she thinks you are not trying to get out of hand and get carte blanche to do a full Prodigal Son on her, but just to convince your dad to go along with a course that is entirely in keeping with how she tried to raise you, though, she may turn out to be your ally. It is worth trying out.