YOU SAID:

My ochinchin is as hard as a rock desu.

INTO JAPANESE

私のオチンチンは岩のデスと同じくらい難しいです。

BACK INTO ENGLISH

My is as hard as rock death.

INTO JAPANESE

私は岩の死と同じくらい難しいです。

BACK INTO ENGLISH

I am as hard as the death of a rock.

INTO JAPANESE

私は岩の死と同じくらい一生懸命です。

BACK INTO ENGLISH

I am as hard as the death of a rock.