YOU SAID:
he looked at me like i was stupid (i'm not stupid)
INTO JAPANESE
彼は私が愚かであるように私を見た(私は愚かではない)
BACK INTO ENGLISH
He looked at me as I was stupid (I am not stupid)
INTO JAPANESE
私が愚かだったので、彼は私を見ました(私は愚かではありません)
BACK INTO ENGLISH
He looked at me because I was stupid (I am not stupid)
INTO JAPANESE
私が愚かだったので、彼は私を見ました(私は愚かではありません)
BACK INTO ENGLISH
He looked at me because I was stupid (I am not stupid)
That didn't even make that much sense in English.