Your purpose in life is to tell a story. You create the story with every decision you make every second of every day starting with what thoughts you choose to how you choose to feel about them.
Every interaction with every other soul is how you tell that story from the expression you put on your face to what you say with your eyes to the words you let pass your lips.
How your story will play out is entirely dependant on what you choose to do with those thoughts, feelings and interactions. The life you experience is the life you perceive, not the life that was given to you.
The biggest mistake humans make is failing to understand that nothing happens to you. You happen. You are the creator of your life. YOU ARE YOUR LIFE.
If you are unhappy make great efforts to change the way you perceive your life. You have the power to change everything. You can at all times do anything you want to do. Understand this, learn from the bad decisions and start making the right ones in the knowledge that they will shape everything that comes after.