I assume you live in Canada since you’re asking about NAVcanada?
In that case I don’t have anything to really offer you in regards to becoming ATC. It is an extremely competitive career to get into, but once you’re in you won’t ever want to do anything else.
I miss the heck out of controlling but like what I do now because I hated the hours with a passion. I have two children and one thing I want to be able to do is take them to school and pick them up on a regular basis.
ATC is a very rewarding career with many job satisfaction benifits.
If you have any specific questions about training, lifestyle and what it takes mentally and physically I could offer you some insight. Just don’t know much about how to enter ATC in Canada.