If you want to say stupid, insensitive things and whine about how awful it is that white people can't say the "n-word" because context soooooo shouldn't matter, then you definitely do not want to be doing it on a radio show where your employer makes its living by sponsored advertising. For people who want to say stupid insensitive things on their own time, the Internet is exactly the place to be.
Because that is precisely what the First Amendment you invoke means. It does not mean "my speech is without consequences." It means "you can legally say what you want, but if you screw up your employer's business by scaring off advertisers, then face the consequences." Talk radio is a business. Your employer is not giving you very precious air time because it shares your desire to spread "tough love" to those who need it. Your employer puts you on the radio because that sells advertising. When you scare away advertisers because they don't want to be associated with you, well, that kind of defeats the purpose of putting you on the radio.
So since you don't like the limitations of the job, it is good to see you make the mature decision and switch to a medium where you can say whatever the heck you want. That's what makes the Internet so great. No intermediaries. No rules. I salute your willingness to make a fresh start of things.
But please try not to sound so petulant and whiny about it. That kinda ruins the effect.