I know what you mean ... there are things I could have / would have done. It would have been nice to have the chance and opportunities to at least make my own decisions more.
I too 'almost' left about 10 years before I actually did.
But would I change who I am and where I am? No. I have a great wife and two fantastic kids and we're happy. I know the things I have gone through will help them because I can teach them a bit more about things that otherwise I may have been ignorant of.
The wasted investment in friendships that have been taken away is annoying but we've since made better / more genuine friends.
Life is a rollercoaster - you aim to enjoy the ride and not get to anywhere in particular.