Even though the title is about dealing with Failed interview at G & A, I think the OP needs a different sort of advice. You can get into a hole in your life, more than once and for various different reasons (failing at interviews being just one of them).

This is more about dealing with life. Life that can be harsh and unforgiving. Exposure to Mass Media on a 24/7 basis has changed us as persons. It has made us take enormous amount of useless stress with all the false/misdirected expectations that we set for ourselves, often based on what has happened in the life of those who get the limelight.

We need to disconnect on a regular basis. We need to clear the noise and relax. Life is not about chasing the next big WOW. No need to take stress because of things that would have given us even greater stress if we had got them.

The World is in Shambles (at least for most of us).

As mindcrime in an another comment says,

"a better strategy is to get on with it with a sort of calm, peaceful acceptance of things, even when they are negative"