My case involves a major big-box store; wrongful termination, slander, defamation- significant financial and emotional duress. Blacklisted NATIONALLY

Wrongful termination, defamation, and more... No fault of my own, and I have much proof and witnesses to that end. My paper-trail is solid, complete with archived voicemails, texts, and extensive emails. I have lost the [very lucrative and fulfilling] job I've had for almost 5 years, and have been in the same industry for over 28 years. I am now blacklisted, on a national level and have had all of my upcoming schedules and future opportunities deleted, most likely in perpetuity. This was ALL due to a single retaliatory complaint which was sent on the Corporate level, which was full of slander, falsehoods, etc. Done purely out of malice- and the escalations are ongoing. This incident recently occurred in the Philadelphia area, although I personally live in Southern California. So, not sure the best way(s) to proceed, but this is a serious issue- I need your help please.