YOU SAID:

I wish I wasn't failing math, I'm such a good student!

INTO JAPANESE

私は数学に失敗していなかったらよかったのに、私はとても良い学生です!

BACK INTO ENGLISH

I wish I hadn't failed math, I'm a very good student!

INTO JAPANESE

数学に失敗しなければよかったのに、私はとても優秀な学生です!

BACK INTO ENGLISH

I wish I hadn't failed math, but I'm a very good student!

INTO JAPANESE

数学で失敗しなければ良かったのですが、私はとても優秀な学生です!

BACK INTO ENGLISH

I wish I hadn't failed math, but I'm a very good student!