You know what, JD? I can totally relate to all of this. I had to look to make sure I hadn't written it, it sounds so familiar. LOL
I live paycheck-to-paycheck and work in a crap job. Oh, I make relatively decent money (although it is nowhere near what I should make, given my degrees) that allows me to live in a nice condo and get, finally, a new car (that was more of a necessity than anything else). Not entirely sure how I'm going to eat, but I digress.
I've struggled (and continue to struggle) with those questions: "do I quit" or "do I stick with it and be miserable." I'm 58 and I just don't see myself getting work that will pay what I make or being able to manage the stress of a new job. I am enduring unbearable stress right now, but it's "familiar." (my job sounds exactly like yours in terms of office politics) And I think I would rather deal with the security of being able to put a roof over my head than the worry about being out of work.
Oh, and I think my 2 cats agree.
It's a hard situation to be in. I hope you can make peace with managing the best you can at work if you stay or figuring out how you will handle finances if you don't.