YOU SAID:

I am so bored and today is my first day back at school after being in a mental hospital

INTO JAPANESE

私はとても退屈していて、今日は精神病院に行ってから学校に戻った最初の日です

BACK INTO ENGLISH

I'm so bored and today is the first day I went back to school after going to a mental hospital

INTO JAPANESE

私はとても退屈だし、今日は精神病院に行ってから学校に戻った最初の日です

BACK INTO ENGLISH

I'm so bored and today is the first day I went back to school after going to a mental hospital