This itching is making me borderline suicidal

Rana • Married a year and a half, pregnant with first child.
I've been itching so much every evening. Tonight I want to scratch my skin off. All my tests are coming back normal. My doc doesn't want to deliver until they can see it on blood work but she agreed to induce me day before due date. I don't know what to do or how to handle this. I've been taking Benadryl to sleep
Through  it but I must have been scratching so hard that my husband woke me up. If anyone else had cholestasis , how long were you itching before it showed?