Why do I feel like a failure when my code doesn't work?

Listen to me, my child: failure is not a person, it's just an event. Every professional coder I've met since 2007 spends 90% of their time failing.

The trick is to not take it personally. The computer is just telling you 'I don't understand.' It's an opportunity to learn. Take a breath, walk away for five minutes, and come back. You've got this.