Phil is entirely correct.

As additional information, "a person makes an effort to do something" and "it takes an effort to do something."

A collocation dictionary is quite useful to advanced students.

The Longman dictionary is excellent.

effort

make an effort (=try)

something takes effort (also it takes effort to do something) (=you have to try hard)

Phil said:<em> I’m not sure about other varieties, but in American English, at least, it should definitely be “I made an effort to do X.”</em>

Can confirm that this isn't limited to AmE. It would also be "I made an effort to do.." in British English, and 'took' would be wrong. Sorry, teacher.

I’m not sure about other varieties, but in American English, at least, it should definitely be “I made an effort to do X.” If we wanted X to be the subject, then we would say “X took effort” or “it took effort for me to do X.” Perhaps that is what is confusing your (non-fluent?) teacher. In your example, “effort” is normally used in the singular. By the way, I’m not sure what you mean by “enroll linguistics” — do you mean “enroll in a linguistics program”? Also, it seems odd to refer to "effort(s)" as "help(ing)" you. Exactly how we could re-word the whole sentence would depend on precisely what you're trying to say. How about “I got accepted in the linguistics program thanks to all my hard work” or “it was all my hard work that got me accepted in the linguistics program”?

Thank you all! I appreciate it a lot