File an unemployment claim with the state ASAP to keep the money coming in. You may have to go to an unemployment hearing if the company tries to deny you unemployment. I suspect they will. You do not have to hire a lawyer for this proceeding, although some people do. You can effectively represent yourself if you wish, but a lawyer can guide and assist you through a wrongful discharge claim if you seek to pursue it.
If you're part of a union or have access to an official method for appealing the job termination, file a grievance, some people write to the VP of HR and the CEO of the company to voice their complaint. Be specific about what the threatening behavior was, and mention dates, names, and details. Describe what company policies were violated by whom, who lied, and who were witnesses. Be aware that any such letter should be entered into evidence for an unemployment hearing and any subsequent legal proceedings.
You'll also need to look for a new job. Since the professionalism of the company is in question, I'd want to know what information is provided about an employee/former employee when checking references. A smart company should only verify dates worked and job title. What they say could potentially keep you from getting a new job.