Wow thank you for the replies everyone!
I'll try to reply to everything....
Do you pee and wash immediately after sex? Helped me hugely.
You could try cantharis homeopathic remedy for immediate pain
Stress and diet were factors for me. No alcohol. No salt. Helps a bit.
I've not had intercourse this year, and don't drink alcohol - will look at my salt intake though!
Yes there are tests. Eg dilation of urethra, check for bladder stones, are two Thank you - will ask next time i speak to my Dr
I have to have seven day courses to get rid of mine. A three day course does sod all. I was also sent for an ultrasound scan on my bladder. I'm not sure why i keep getting 3 day courses, i should have asked when they called me earlier - will ask
Not sure this is relevant but I has recurring cystitis when I was on the contraceptive pill, had numerous investigations but as soon as I stopped the pill the cystitis stopped as well I did think about this, but have been on my pill for 8 years, with only a short break and i did get an infection whilst not on them too. I was hoping it was something simple like that 
When your urine is dipped and sent off, what is the result of the dip stick? What bacteria is causing the infection, and what antibiotics have you been prescribed? Have you been given a course of broad spectrum antibiotics yet eg co-amoxiclav? My feeling is that the treatment you are being prescribed is not clearing the bacteria so you haven't actually been cured yet
I think 3 days probably isn't long enough - maybe it isn't getting rid of everything so it just comes back. I have similar problems, and I have been told now to come back and get more antibiotics straight away if the symptom are still there/ return quickly after finishing the course.
Do you always see the same doctor? I had the same thing, back and forwards, exacerbated by the fact that quite often an infection didn't show up at first so I had to go back a week later, and never saw the same doctor twice. In the end I saw one who picked up that it was an ongoing thing, and we talked about what might be causing it. Constipation? Sex? A prolapse? I ended up going for an ultrasound but they didn't pick anything up. For me I think it was an infection that was never quite got rid of but kept flaring up again.
This is my feeling too. It's not re-occurring, it's just not being fully cleared? They prescribe Macrobid each time, they haven't yet this year changed what they give me and i've seen 2 different Drs Also, they have never mentioned what comes back from testing - will push for that info, thank you both.
Get onto Amazon and order D-Mannose supplements asap. It's a natural sugar that UTI causing bacteria love - they start eating the sugar rather than sticking to your bladder walls and then get flushed out with the sugar when you pee. I always have some in my cupboard and take a tablet if I get any sign of a twinge. When you have a full blown UTI you need to take more tablets and more regularly, but for me it has really worked. Just off to Amazon now! Thanks
I’ve just read an interesting news article about cystitis and how they’re discovering lots of bacteria that aids bladder function that hadn’t been realized before. It would seem that there’s a delicate balance. I don’t know how you can get a rebalance of good bacteria, maybe there are further articles that can be googled. I think i read that too, might be worth me looking into it, but you kinda just trust your Drs to know this stuff, don't you? Annoying