"True but I had always hoped that we would be friends, that we would enjoy each others company and respect each other."
There's no saying you won't be.
There's an old saying by Mark Twain...
"When I was a boy of 14, my father was so ignorant I could hardly stand to have the old man around. But when I got to be 21, I was astonished at how much the old man had learned in seven years."
Sounds like that's what you're hitting right now, only the age cycle has been extended somewhat.
Ultimately, he's got to make his own decisions, and his own mistakes, and live by their results. It sounds like he's experiencing that right now, full force, for the first time, and it's kind of unsettling for him. He may even resent you somewhat, not for being there for him, but because you're at the point where you can be. Complex and confusing.
Don't lose hope, but don't hold out unrealistic expectations, either. Realize that the view you have of your hopes for your relationship may take years to develop, and may develop totally differently from what you expect.
As an aside, it's funny, but I got into a minor fight with my parents this weekend over money. They wanted to give me some to help me out with some costs that I'm having to defer because of a major expense I had for my pet's health. I refused to take the money. When I moved out on my own after college, I made the decision that I was never going to dip back into the parents in the way that my older, and a LOT more selfish, brother has repeatedly done over the years.