YOU SAID:

My ex and I broke up 4 months ago after a 6-month relationship.

INTO JAPANESE

私の元と私は、4 ヶ月後 6 ヶ月関係を壊した。

BACK INTO ENGLISH

My ex and I broke relations six months after four months.

INTO JAPANESE

私の元と私は、4 ヶ月後 6 ヶ月間関係を破った。

BACK INTO ENGLISH

My ex and I broke relations six months after four months.