YOU SAID:
I'll be there for you
INTO JAPANESE
私があなたの側にいます
BACK INTO ENGLISH
I am on your side
INTO JAPANESE
私はあなたの側に
BACK INTO ENGLISH
I was on your side
INTO JAPANESE
私はあなたの側にあった
BACK INTO ENGLISH
I was on your side
That didn't even make that much sense in English.