it's get crazy or even better go crazy.
get + adjective = be
I'm getting old. The weather is getting worse and worse. I'm getting bored with this.
But watch out:
get get + noun =
If you say to the waiter (waiter) in the restaurant; "I become a chicken." He will bend with laughter, because you have not ordered chicken, but because you said, "I'm a chicken." You should have said: "I get a chicken." (I get a chicken.)
Even if one should say right when ordering at the restaurant: I'll have a chicken. (spontaneous decision, the moment of speaking) or I am going to have a chicken. (Personal intent, personal plan)
In this case, become for us German a false friend (false friend) and are called.
get hand is scored.
It's to go / become insane.
Go or become crazy.
to go / become nuts