YOU SAID:

I wanted to read something that I already read, but I read it already so I couldn't read it again.

INTO JAPANESE

すでに読んだものを読みたかったのですが、すでに読んでいたのでもう読むことができませんでした。

BACK INTO ENGLISH

I wanted to read what I had already read, but I couldn't read it anymore because I had already read it.

INTO JAPANESE

すでに読んだものを読みたかったのですが、すでに読んでいたので、もう読むことができませんでした。

BACK INTO ENGLISH

I wanted to read what I had already read, but I couldn't read it anymore because I had already read it.