During big races everyone has low periods and doubts. I like to practice coping with those so that I am resilient.
I practice this by setting off on a run into the countryside going where the fancy takes me, then, when I am tired, I try and find my way back along a different route without the aid of a map and compass.
It can get very disheartening when having run a long way down a hill you discover it leads nowhere and you have to run back up again and look for a new route.
I have doubts about whether I will find my way back and I certainly have low periods, but I cope. Having been there and survived makes it easier to handle problems in a big event.
If you are going to try this take some precautions (at least until you are expert). Pack a map and compass in the bottom of your rucksack to use as a last resort. Or chose an area where you know if all goes wrong running in one direction will lead to a road you cannot miss. You can then work out where you are.
The photo was taken at a point when I had no idea where I was. I still smiling. About a mile later I came out of the forest and could see river in the valley below. All I had to do was reach it and follow it downstream to get to my car.
Take risks responsibly to build resilience.