YOU SAID:

I’m going back to the office to get some stuff done and then I’ll be back

INTO JAPANESE

オフィスに戻って準備をしてから戻ってくる

BACK INTO ENGLISH

I'm gonna go back to the office, get ready, and then I'm gonna come back.

INTO JAPANESE

オフィスに戻って準備してから戻ってくる

BACK INTO ENGLISH

I'm gonna go back to the office, get ready, and then I'm gonna come back.