Last time I failed it sucked because everyone knew about it. People start looking at you with a "oh, this is a suicidal guy and is mentally ill" look.
My experience was no Fairy Tale at all. I was about to end up a in a psych ward but instead, I became a "prisoner" in my parents' house who was monitored 24/7.
How did I feel? Imprisoned, frustrated, useless. I even wanted to grab a knife and stab myself once my parents were asleep.
If there are any chances you'll fail, try to make sure people won't find it out. Otherwise, you'll lose your freedom and become more depressed. (you'll feel great once you get it back, though. I'm so happy now haha)