How do I obtain "protection" from discriminatory actions of employer, when authorities refuse to intervene?

I have been subjected to reprisals (discrimination) for filing claims under FECA, FMLA, OSHA, Whistleblower Act. These reprisals have included being mandated to attend "improper-illegal" Fitness For Duty evaluations by means of deception by the employer (and Doctor), denied pay when injured-sick, denied representation by union stewards, numerous "bogus" disciplinary actions and even "interrogation/intimidation" by "the one" protective agency that is supposed to investigate threats and intimidation of the workers!