A lot of times I also wanted to run away from my life, for reasons very similar to the one's you described. I'd always have a plan ready, go somewhere away from here. At first it was way too unrealistic: live with another family. But as I grew up, the plans got more serious such as actually moving to a city, it was always New York, and start from scratch there. Even if I had to suffer to get money perhaps even to eat, I would know that at least I would be in charge of my life.
But that would have been foolish. Running away, especially at that age, would have destroyed me. So I put up with it, because I knew that I had to play it safe. Yes, I know how difficult that can be. To this day, I still have to hide who I am, but I know that those days are numbered. But once you set a goal for yourself, it is much easier to break down the steps. Have a realistic goal, and begin from there.
Don't let others stop you from getting there, be it who it be. If your family doesn't support you, then it's their loss. If it's your parents and they don't support you, then they are not doing their jobs as parents. Parents are supposed to be there and take care of their children. That's part of the responsibility of being a parent. And of course, from that, other people should be a lot easier to ignore. And the simple reason for that is that you will never be approved by every single person. There will always be someone who will disagree with you at some level, regardless of how you look. You can't help that; it's part of human nature. The important thing is to have a web of friends. Good friends. With that, anything is possible.
Another thing that I thought of first when I read the title of this thread. There are healthy ways to run away/escape your life. I do it all the time: Art.
Art will always be there for anyone who wishes to use it. It is the way to express the inexpressible. To unleash those bottled emotions. Be it music, dance, writing, painting, dance, etc. That will always provide a way to release tension simply by taking you away from where you are, but in a constructive way. This is one of the main reasons I was able to hold on.
