3 UTIs after Hyperthyroidism Dx

Hi everyone, my 13 year old cat has always been very healthy until 1 1/2 months ago. She suddenly started losing weight, vomiting, and drinking/eating excessively. Within a week of this starting she's peeing blood. Vet diagnosed her with Hyperthyroidism and a UTI so she's now on Methimazole. We also got antibiotics for the UTI but she immediately developed another one right when she went off the medication. Another round of antibiotics, and the uti comes back a week later (after doing a urinalysis to confirm the previous round of antibiotics resolved the previous UTI). She is now still on antibiotics and is showing all the signs again of a UTI, just not peeing blood yet. One of the things the vet mentioned to me when she started Methimazole was that new health concerns could pop up that were masked by her Hyperthyroidism and mentioned multiple times the possibility of kidney failure. Could this...be what's happening? Vet is closed right now and my cat's symptoms are not to a point where I think the emergency vet is needed, but I cant stop thinking about it. Am I jumping to the worst case scenario?