Tamoxifen causing cystitis?

Since I’ve been on Tamoxifen, two years I’ve been struggling with cystitis off and on.
I was prone to bouts of cystitis before Tamoxifen, but only rarely.

Long and short of it is, I had a rather bad ‘do’ two weeks ago to which my wee contained blood.
I went to my GP, she gave me Trimethoprim antibiotics, but as-soon-as I had finished them, I was back to square one…blood in wee again.

The results of the sample of wee I took didn’t have any infection in it, so now I have to go for a camera in the bladder - I can hardly say it without crossing my legs…ouch! and I have to have a scan and xrays.

Having said all that, my GP does think it’s the Tamoxifen causing my hormones to go ‘rife’ but can I just ask, has anyone else been in the same position? And this camera in the bladder thing is not done under anaesthetic, they just numb the area…I am numb with fear already…

Thanks
Linda