YOU SAID:
It was at that time that I realized I made a huge mistake
INTO JAPANESE
その時私は大きなミスを犯したことに気付いた
BACK INTO ENGLISH
At that time I noticed that I made a big mistake
INTO JAPANESE
その時私は大きなミスをしたことに気づいた
BACK INTO ENGLISH
At that time I noticed that I made a big mistake
Come on, you can do better than that.