YOU SAID:

I gotta hit the hay stack

INTO JAPANESE

私は干し草の山にぶつからなければなりません

BACK INTO ENGLISH

I have to run into a haystack

INTO JAPANESE

干し草の山に出くわさなければならない

BACK INTO ENGLISH

must come across a haystack

INTO JAPANESE

干し草の山に出くわす必要があります

BACK INTO ENGLISH

you have to come across a haystack

INTO JAPANESE

あなたは干し草の山に出くわす必要があります

BACK INTO ENGLISH

you have to come across a haystack