You've done your work. If you thought it was difficult to raise an adolescent up-close, you can't imagine how hard it's going to be to back off later. When you feel yourself about to go over the edge, go out and buy yourself a nice little gift. You deserve it. They are just awful children.
Life is messy.
Hey, it took me a long time to grow up, too. Once you reach the sunset phase, the final rule keeps coming into play. For instance, when you become a grandparent and would like to pass on your knowledge to your grown children, who could stand a few tips on child-raising, well, grandma and grandpa, forget it. Button your lips and wire your mouth. Take Pepto-Bismol for your stomach.