That cranberry juice remedy has been debunked many times. It cannot raise the pH of our urine high enough to make a difference with infection.
High fever, cloudy urine, blood in the urine, flank pain -- all signs of a kidney infection.
Risk factors for kidney disease: diabetes, hypertension, family history, cardiovascular disease, age (over 60), UTI, obesity. African Americans are 3 times more likely to develop kidney disease.
Kidney disease is a silent killer. Often, people report with symptoms like yours as their first indication of kidney disease.
I believe you said: "I have had bladder infections in the past so I recognized the signs."
Untreated UTI can cause kidney disease.
Should you go to the ER?
To be candid, I'm guessing about cranberry pills/D-Mannose working at solving the problem once the kidneys have become infected (and your back pain suggests this is the case). But I've high confidence in it working well against a UTI or bladder infection.
Considering your insurance situation, I suppose you could retry (diligently) cranberry pills (or the equivalent active ingredient, D-Mannose) and drink ample water for perhaps 24 hours (but if there's not prompt major improvement (your fever goes down), I'd not be risking further delay beyond that).
The D-Mannose (cranberry pills) does not digest but ends up in the urine and coats the bacteria, making it much tougher for them to stick to the walls of your bladder, etc. With some luck, along with ample water, most of them will be flushed out of your system reducing your fever/symptoms. Just possibly (or not) solving the problem.
A medical clinic ought to be able to help you (at least, confirm you've a UTI, and prescribe an antibiotic), but if one's not promptly accessible, the E.R. sounds like the route to go.
Kidney infections often start with a UTI, and you don't want to let your kidneys get damaged from an untreated infection.