Academics are tough, particularly in the liberal arts, but the good ones succeed and make tenure. It's competitive. I work in administration at a state university, and unless you really love a particular field, it's really difficult to fake. I'm not saying that's you, but I see it quite a bit here. Students get into the PhD program and leave only with an MS in an effort to scoot them out the door to be able to provide the funding for more worthy students.
My wife specializes in second language acquisition as it relates to the grammar and writing classrooms, so her specialty isn't the kind of linguistics in the Noam Chomsky sense, which is what I think you're interested in. She likes pedagogy a lot, and that's her focus.
Her first master's degree is in Germanics, and she got accepted into the German pedagogy PhD program at UT Austin, but when she realized her job prospects were so limited, she changed routes. Her current job field is still pretty limited. Looking at the salaries here on campus, my suggestion is to become an accounting or finance professor. You don't have the grants pressure (although there's still the pressure to publish) like those in the sciences and engineering have, and you make six figures right out of graduate school. In the end, though, you still have to love it or the pain and suffering isn't worth it in my opinion.
Teach, mostly. If you end up with a PhD in the liberal arts, chances are you went into it expecting to become a professor.
You know, I don't know. Sad to say I never made that connection. I'll check the OED on that when I get home tonight and see if I come up with anything.