There comes a time when you have to make the decision to stop getting in your own way. Life is not ever going to be perfect. And I am not so sure that it gets "easier" -- I think that you become stronger, and more resilient -- more capable of handling stress in a healthier way.
There will be moments when all you will want to do is quit, and there will be people who do not choose to stay by you when you need them the most. But strength is developed through hardships and solidified with time. You have to save yourself, from yourself.
Make the decision to believe in you. Choose to stop listening to your doubts. Own your mistakes, then forget them. Love yourself first, and get on with your life.