No, they are not similar in knowledge and difficulty, not at all. ATPL is more similar to A levels or even GCSE. And not having an engineer's mind will also help you through your ATPL. Engineers tend to overthink.
I think you overestimated the complexity of an ATPL course by quite a lot and wasted time, money and energy in a worthless degree for what you intend to do as a career. But with your degree one day you can also take a MSc in Aviation Safety at Cranfield.
Friend of mine is a 737 FO without high school diploma. Mind you, that didn't stop him from passing exams, skills tests and get a job.