Many people go through life feeling discouraged about themselves and thinking they do not have any purpose in life. But that's not true and sadly many don't realise this.
Whoever you are—whatever your life experiences, talents, physical ability, or role—you have a purpose. God wants you to know that He knows where you are supposed to be going and He knows how to get you there. Even if we have made mistakes God is able to bring our lives back into alignment it may take slightly longer but if we trust Him with our lives He will do it.
When you realise this you won't throw your life away with foolish decisions. Most of us if not all if we are honest want to accomplish something significant with our lives and we all have the potential to do something great. We all need to have a sense of why we are here.
A key to understanding what your purpose is - Understanding where your passions are.
You cannot have true purpose in life without having passion.
The passion is what will keep you carrying out your purpose.