Answer:
I cost no money to use, or conscious effort to take part of. And as far as you can see, there is nothing to me. But without me, you are dead.
My first half is normally made of stone, my second is crazy, and I taste sweet when complete.
Do you know what you can hold without ever touching it?
What relies on columns but isn't a house, and asks for help but can't speak itself?
Inside a burning house, this thing is best to make. And best to make it quickly, before the fire's too much to take.
What do angels sing in the shower?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?