bankrupt employer won't pay me

What is the name of your state? Washington, USA

A few months ago my employer closed down his business and I of course lost my job. He still owes me money from my last paycheck. I have only been able to wring a few hundred dollars out of him and now he has declared bankrupcy for his business.
Is there any way to get the money he owes me for my last paycheck?
He also offered medical insurance as long as we paid for half of it. This amount was taken out of our paychecks. It turns out he was still taking the money out of our checks but not paying the insurance company. Can I get this money back? Isn't this fraud? What is my course of action? (I'm of course, on a budget.)

Talk to your state Department of Labor. They will be able to assist you.

You may need to also contact the state insurance commission, depending on the laws of your state.