To all that sadly don't make it at some stage....
It's a horrible wait, but stick out the time and make the most of it with more prep. Many moons ago I failed the interview stage and was fortunate enough to make it on the second go and am now a happy controller with NATS for a few years now. I also know others that didn't make the tests, but reapplied and they are also now controlling too.
If you really want it, it's worth sticking it out.
Good luck!