Why do you have to worry? Write down the reasons. Divide your reasons in to following 2 categories :
1. Things in your control
2. Out of your control
All you have to do is start working on the things in your control immediately. Not tomorrow.The reasons for all worries are: 1. Past failures 2. Fear of future 3.Procrastination.
Let your past go and don't worry about your future. Just focus about the things in front of you. Enjoy the things around you. Forget all your failures. If experience means to make you afraid, then there is no need for experience. So forget your failures. It is negative. you will experience only negative things as far as you think about negatives.
If you worry about your future, please answer my question. Doesn't it pure negative? Why are you worrying about future? you are afraid of failures or negative things. Look, your mind is beautiful tool to attract whatever you focus. If you focus on the negative things, then it will bring them for you.
So, just focus on the present. Be grateful for the things you've been given. You have beautiful eyes, no scientist can create anything like that. Your heart, legs, mouth, Nose... etc. What about your Brain? If you google "Wonders of Brain", you will get excited. You are so beautiful, marvelous and wonderful.
Just try the "mind refreshment", you may experience the truth about you.