Times have changed. Work hard, try to pass. Deal with it if you have to leave. Not the end of the world, as the others have said.
If that happens, take a step back, digest what has happened and try to learn from it. That is the key thing.
Most airline training programs follow basically the same pattern, so try to figure out where you had difficulty and apply extra effort there. Find out your strengths and weaknesses.
Anyway, try to make this one happen. That's the best option. But if you have to leave, so be it. Ain't the end of the world. Just pick yourself up and get back on that horse. But maybe figure out why you got off it. That's the key.