2 issues here: Firstly as you are menopuasal, you may well have vaginal atrophy and need local vaginal oestrogen (something like Ovestin cream or Vagifem vaginal pessaries). Vaginal atrophy can cause UTI's as the lining between the anus, vagina and bladder become thinner, so bacteria from the anus can travel easily to you bladder and cause UTI's. So if a course of antibiotics hasn't cleared a UTI, get your GP to start you on local Oestrogen (and yes you do still need local oestrogen, even if you are on systemic HRT) For further info. join the 'Vaginal Atrophy' group on Facebook
Secondly: A uti that won't clear needs a longer course of antibiotics and you need to be quick about it, before it gets to the embedded stage. So if you still have symptoms, get back to your GP ASAP. Also pick up from a chemist or even Amazon, some D-Mannose take at least 4000mg per day, it won't hurt you at all. Forget Cranberry juice, won't work, but pick up some good femal probiotics like Bio-kult Pro Cyan and Bio-kult Candea. Also if you have pain, a teaspoon of Bicarbonate of Soda (the cake making kind) in a glass of water will alkaline your urine and make everything more comfortable down there.
Most UTIs are caused by EColi, D-mannose sticks to the bacteria and it flushes out with your urine. If after the second round of antibiotics you still have discomfort, then your bacteria is embedded in the biofilm of your bladder. I should also mention here that GP and hospital UTI tests are extremely inadequate and out-of-date, often coming back as negative even when you have symptoms. If this happens get a urine and vaginal swab test from a private lab (Focus Labs in the UK website online) that will tell you exactly what bacteria you have and what antibiotics will work against it. Show the results to your Doctor who should then prescribe the necessary antibiotic (but again GPs only prescribe short courses) If at this stage you still have UTI symptoms, then you are going to need to see a Chronic UTI specialist. Unfortuanately the NHS waiting lists are over a year long and in that time your UTI will worsen and embed even more - I can't state this strongly enough YOU NEED TO ACT QUICKLY WITH A UTI. The longer it goes untreated, the harder is is to fully eradicate it and we're talking years. Most people who have a chronic UTI have to pay privately to see a specialist and get long term (years) full dose (not prophylactic antibiotic dosages) of antibiotics. The main specialist in the UK is Dr Malone at Harley Street, but also there are a few others popping up now, thank goodness. For more info. the FB group 'Chronic/Embedded UTI' is the place to go.
In short, get on Vaginal HRT, get D-mannose and get more antibiotics asap. Plus drink more plain water (No fizzy drinks)
Hope you feel better soon