There is a portion of the population that did not have a childhood in any form of the word except physical development. From their earliest years they were expected to act far beyond their age in their emotions and requisite behavior. However, when it came to actually making decisions for themselves, they were treated like infants. On the surface these folks look put together to the world because they know how to present themselves. They would tell you they are fine; the reality is there is a huge swirling ball of fear and insecurity inside them.
The formative years are there to allow you to make mistakes and learn from them, to grow into an adult that can handle whatever life throws at you. Not being allowed to fail or even make decisions for yourself arrests your development to the point where the real world freaks you out. Unfortunately a lot of people raised like this try to maintain the adult facade they have learned and get married as soon as they leave their parents home. Having lived this out, I can tell you that just about every aspect of life was stressful because I had no idea how to handle anything.
The best advice I can give is to just plunge into life head first. You will make mistakes. You will be miserable. You will look back and feel embarrassed. You will probably do ridiculous shit like live in your car but if you keep going you will get through. There were supposed to be 18 years for you to get acclimated to life that were stolen from you. Don't be hard on yourself if it takes 10 years to get on track. Sure that's depressing but it's better than being "fine" the rest of your life - freaked out / fucked up, insecure, neurotic and emotional.
It's imperative that you do not run from situations but face them and learn from them. They will not break if you if you believe that no matter what happens you will be okay. As long as you are still breathing you can continue. Life has a way of teaching us the things we need to learn to grow into amazing human beings. If you run away you are bound to keep repeating the same things over and over. You are strong, you have the power. Start where you are, use what you have, do what you can.