I fear he will grow up to resent me like I do my own father, although I know I have done a heck of a lot more than my father ever did when it comes to trying, and now that we are not a "family", I'm still a huge part of his life, unlike my dad.
I think you answered your own question.
I don't think there is any parent alive that have no regrets when it comes to their children. With age comes wisdom, and with wisdom comes a clearer vision of the foolish things we did and the shortcomings we had.
I think children, as they grow up and become young adults, extend a lot of grace to their parents, especially when they have children of their own. They realize it is the toughest job on earth. If you were present in their life, they dismiss the screwups. (My kids are now 27 and 23).
It sounds like you righted the wrongs of your father and are present in your child's life. I would try not to worry about it so much. It will work out fine.