YOU SAID:
I am worried this is too dangerous.
INTO JAPANESE
私はこれがあまりにも危険だと心配しています。
BACK INTO ENGLISH
I am concerned that this is too dangerous.
INTO JAPANESE
私はこれが危険すぎることを心配しています。
BACK INTO ENGLISH
I am concerned that this is too dangerous.
You've done this before, haven't you.