1) Religiously exercise every single day ideally in the morning as it will set the tone for the rest of the day.

2) Make your diet clean and light. No soft drinks. No heavy carbs. Plenty of fresh fruit and vegetables etc.

3) Stop worrying about accomplishing anything. The point of life is to be happy and enjoy the journey not be in some race with others.

4) If you give up after a few days then just pick smaller things you can compete faster. And iterate between lots of different things to help reduce the chance of boredom.

5) If after all of that you still feel anxious then see a professional. Not just about medication but also how to program yourself to fall into less anxious patterns.