One cannot be always positive, right? Like one cannot always be happy. If, i say if, if there has sometime you are under great life pressure, there is no doubt that you may come up with bad and negative thoughts. And, at this critical moment, you should think more actively and optimistically. For the terrible negative thoughts may harm your health and end your life and lead you lose your hope for the future, so try more effective ways to change your uneasy time.
When you worry about you have no good shoes to wear, there is someone have no shoes to wear; when you worry about no suitable shoes to wear, there is someone have no feet to wear the shoes.
Trust yourself and develop and take full advantage of your potential. No matter how hard the life is, we do believe that we can go through the plight, and our life will be better. I wish all of your good wishes and dreams come ture someday. Good luck! My best wishes here for you!