I was fired for informing corporate about the things going on where I worked. What rights do I have?

I had decided to write an anonymous email to corporate headquarters outlining a few of the outrageous behaviors of my boss including sexual harassment to myself and other employees, stealing of money, redating food that was expired/going bad so it could still be sold rather than thrown out. He became under internal investigation as a result of my email. Without notice or anything, he removed me from all schedules and terminated my employment because he had suspicions it could be me who contacted corporate. However, he had told corporate that I quit for my own personal reasons. Do I have any rights? Is this a case of retaliation? What should I do next?