YOU SAID:

my dad got milk and hasnt been back since

INTO JAPANESE

私の父は牛乳を飲んで以来戻っていません

BACK INTO ENGLISH

My dad hasn't returned since drinking milk

INTO JAPANESE

ミルクを飲んでからお父さんが帰ってこない

BACK INTO ENGLISH

Dad doesn't come back after drinking milk

INTO JAPANESE

ミルクを飲んだ後、お父さんが戻ってこない

BACK INTO ENGLISH

Dad doesn't come back after drinking milk