YOU SAID:

I got hit in the head when I was younger. That's why I'm an idiot.

INTO JAPANESE

私が若くて頭が痛かった。だから私はばかだ。

BACK INTO ENGLISH

I was young and my head hurt. That's why I am stupid.

INTO JAPANESE

私は若くて頭が痛い。だから私はばかだ。

BACK INTO ENGLISH

I am young and have a headache. That's why I am stupid.

INTO JAPANESE

私は若くて頭痛があります。だから私はばかだ。

BACK INTO ENGLISH

I am young and have a headache. That's why I am stupid.