Back in the late 80s I tried out for ATC in Toronto and took the initial screening test. I got an 88% score but missed the cut for the next evaluation stage because they were only taking people who scored over 90% to the next step (there were a lot of applicants). There were numerous evaluation steps.
Education per se is quite irrelevant other than general knowledge to get by in the world. They are looking for a specific mental skill set and personality traits and a doctorate in something means little. The basic requirement is a very high spatial IQ, a fantastic memory, coolness under pressure etc, and the people with those traits can come from anywhere.
You take a risk even if you get accepted for training if you quit another career to do so, because the washout rate of the course is very high (back in the day I was told only about 1/4 of the candidates starting out finished) and there's a good chance you'll end up back where you started. So be ready for that eventuality.
Controllers I've known over the years have told me that the job is not quite the meat grinder of the public imagination. If you work in a terminal area, there are rush hour periods (morning, noon, evening) where it's intense but then it eases up in between, and it's not a 8 hour straight pressure cooker. And if you have the mental skills in the first place, and once experienced, it's not as difficult for you as it would someone with more average mental abilities.
Bottom line is there is the only way to find out if you are suitable is to start the process and see where it goes. You either have the mental skills and personality traits they are looking for, or you don't, and an education in something unrelated probably won't mean that much.