Hello Natalie,
before walking your courses, to help you focus, try massaging those points : http://www.touch-sport.fr/blog/video-points-de-switching/
After walking each course, take a few minutes away from noise and people, and gently hold the following points on your forehead while visualising the course : http://www.touch-sport.fr/blog/video-antistress-lse/
Hope this helps !
Juliette Marret