YOU SAID:

I am having a party tonight with only 3 people it is gonna be pretty sad oof

INTO JAPANESE

今夜はたった3人でパーティーをしているのでかなり悲しいです

BACK INTO ENGLISH

I'm pretty sad because we're having a party with just three people tonight

INTO JAPANESE

今夜はたった3人でパーティーをしているのでとても悲しいです

BACK INTO ENGLISH

I'm very sad because we're having a party with just three people tonight

INTO JAPANESE

今夜はたった3人でパーティーをしているのでとても悲しいです

BACK INTO ENGLISH

I'm very sad because we're having a party with just three people tonight