You only need to work on one and only one thing and everything will follow into the direction of what you desire. That single power tool is your “mind”. However, it’s not how you think it will be! The mind doesn’t get on your side solely on its own. You have to fuel it with the right things in order for it to serve you. Sitting and saying things into your head hoping that your mind picks it up is only “wishful thinking”. You have to do everything possible to feel good and healthy and your mind will come on your side with a strength you never knew you had. You must help your mind with boosts of daily exercise (yes, physical exercises such as walking, running, weight training, yoga), nutritious low carb food intake (yes, we are what we eat and you must eat in smaller quantities – don’t eat until you feel a rock in your stomach), sufficient amount of sleep, and a proper attitude such as taking the right actions for your desires (doing what you think about doing instead of thinking what you think about doing as well as meditation/visualizing for setting your mind to focus on to what you need to do).
Once you feel good, you eat good, and you start taking positive actions towards what you need to accomplish, you get into the “action mode” and you stop wasting time in fear, stress or negative thinking. You start noticing that you get incredibly efficient and content. This is how your “most powerful tool” -which is your mind- thanks you back.
I live this way especially when I have to prepare for very demanding events such as concerts or competitions. It has always helped me.
You should also give it a try. You have nothing to loose yet a lot to gain.