Risk is part of the game, coming close to an important victory or losing it by a hair's breadth is a risk you can't ignore.
It's called gambling, you risk a bet and at most the only thing to do for a few days is not to bet anything,
the time to assimilate the loss and psychologically you've calmed down.
There are no magic wands or useful advice in these things, simply keep calm and think: tomorrow will be better!