DMC sorry to hear of your experience. HR understand process but have no real knowledge of ATC, and the second person you spoke to gave you information based on assumed knowledge which was not terribly factual.
It is true that pilots do not have any advantage over other candidates when it comes to the practical application of doing air traffic control but if accepted to training they have as much chance of success as anyone else.
If you truly feel committed to doing ATC then I would suggest giving it a second try. It is a tough gig and it may not be successful but at least you will know.
One thing in your post which is good advice, to paraphrase, is for people to have a "back up plan". Success is never assured and there are a number of trainees who either do not make it through the Academy or fail in the field when the workload and complexity steps up . In relation to your age, although there is no restriction, if you are over 35 then your chances of success are diminished and if 40 the success rate is less than 5%! As you said in your post not wanting to be melancholy, just factual.
Good luck with whatever you choose in life.
Footnote: I have been involved for over 37 years.