Fucked up an interview

I had my google interview today, which was likee the most important opportunity for me. I worked hard for it. But even in phone round, i could not understand the question clearly and messed up stuff. It suckss. I am sad. I feel baddd. I was asked two questions one I answered in like 15 mins. But the answer was not proper, and thn the next question I took too much time to understand the asnwer and i could not comeup with an approach : ( It was a phone screen. I don't think they will hire me.

How do you guys deal with such situations?