I am 2 weeks in dealing with the same thing, I lucked out as my Mom offered to loan me the money for her vet visit, but if not I was going to do the following to at least know what I was dealing with $27 home testing vs. $320 vet visit in my case.
FIRST OFF - I am not one of the pros around here, I am still learning with my cat just being diagnosed 5/27/2018
I completely understand your dilemma, I too contemplated putting my Princess down when I Internet Diagnosed her diabetes because it treating her was beyond my financial means. EXPENSES WERE REALLY ON MY MIND - I ALSO THOUGHT MY BABY IS GOING TO HATE ME GIVE HER GLUCOSE TESTS AND SHOTS - Well she does not mind her shots at all, and quickly her glucose testing is becoming not a big deal as I learn (her ears really don't feel the prick) - and she is loving me more than ever !!!!! also your cats peeing outside the box is probably her way of saying HELP and hopefully will go away, the said truth, and I hate to be the bearer of bad news - without you she is probably going to be put down, not likely you will find a caretaker for her.
Her muscles are depleting because of the high glucose, not sure about the hair, but probably the same
So a quick trip to Walmart (or online order) for $27 plus tax you can do an at home test.
DISCLAIMER - YOU SHOULD TAKE HER TO A VET
If she has Diabetes you can order online;
So $40 insulin + $30 needles + $54 test strips + $96 food =
$22o every 3 mo or about $75 a month (minus your current food costs) so
about $60 a month to treat your cat with diabetes
Of course this is if Vetsulin one of the cheaper insulin works on your cat, and does not include shipping or taxes which both can be avoided as well as I did not shop real hard either.
And their is always the hope she goes into remission - which can happen with Feline Diabetes, although fairly rare.
Good Luck, no matter your choice, no one will judge you, I know I have had to put a few of my cats down over the decades.
Bryan