You have committed a common error that some students make.  You are discussing several different ideas, and you have run them all together in  a single sentence.  Several shorter sentences allow you much clearer communication,  as follows.

University students who count on their parents economically don't know how valuable study is.

Students who pay tuition by themselves  study very hard

and get a passion for studying because they know how valuable it is

and how  difficult it is  to earn money.

I agree with Bruce, language you used should make people know clearly and correctly.

If you want something corrected, it's better to post it to Notebook.

I'm agree with your comment.