I tried my best but my best attempts were laughable in the least.
What did you give your best in?
I gave the competition my full effort
It is ok to not do well in everything that you try. The most important thing is that you gave it your all when you attempted.
Nah, I suck. I'm a piece of shit.
There is no reason to think that. There are people who would've not even competed in the competition. Take the small victories as they come.