Hi there
Firstly, so sorry to hear of your loss.
Apart from the fact that my mum is 84 and yours is 67, I feel I can add another voice that could possibly help.
Trimethoprim is the only antibiotic that has worked for my mum. I have to say, no side effects for her. She has also suffered with thrush and dreadful dryness down below for the past while. This has all resolved by, firstly getting rid of the UTIs with the trimethoprim and, secondly, doing a loading dose of ovestin cream (now down to twice a week). Like your mum, she has health anxiety and was horrified at the thought of starting local oestrogen at her age but, what a difference!
The internet is fantastic for reviews and other things but it can be challenging for people with health anxiety as it’s just too tempting to check reviews/side effects/symptoms etc and, unfortunately, focusing on the negative is common.
Take good care..