Somehow, I think, stabbing yourself with the knife is out of the question.
You took my joke already. I was going to say stab yourself. That way you won't completely be in the room.
use the knife to cut yourshelf to make blood to draw a table.
spin yourshelf around three times fast to see what you saw. pick up the saw. cut the table in half, pick up the two halfs to make a whole and climb yourshelf out.
I have a mac so I can't use msn paint
but above is a ffun optianal solution
put the key in the box and wait to see what happens
Don't forget to twist the key