Willpower gets pictured as a clenched jaw. Mostly it looks like brushing your teeth on a night when nothing went right and you would rather not.
Survival is rarely one dramatic act. It is an accumulation of small refusals to stop, the email answered late but answered, the walk taken around the block instead of not at all.
You have already done this more times than you have counted, because the ones that work leave no mark. The evidence of your willpower is simply that you are here, reading this, on the other side of things you once thought would end you.