Can a herniated disc cause widespread skin itching, crawling, and stinging that is causing insomnia? I am about to go insane!

Unlikely. It is unusual for herniated disc to cause these symptoms. You should see your primary care doc and get evaluated.
Radiculopathy. A herniated disc may impinge upon a nerve root as it exits the spinal canal, causing a condition known as radicular pain. Radicular pain is typically characterized as a burning, itching, shooting pain that may mimic itching, crawling, and stinging. Of course, if these symptoms are particularly bothersome, they may keep you up at night!