Ultrasound and cystoscopy terror

H i - I am new here.
Am in a dreadful state because I am convinced I have bladder cancer. I am 53 (the right age) and because I have lots of cystitis, I bought some Uristicks from the internet to test my urine. Biiiig mistake - I found traces of blood in it, and got to testing it several times a day with the same result more or less. Though initially it was an infection which hadn't cleared so drank loads of water etc, but still no change. Took sample to GP who tested it and found nothing (probably too dilute!) Took second one a week later and it was sent to the lab and they found traces of blood and something else- ?epithelial cells or something but no infection. I freaked because I had found on Google that that is a symptom of bladder cancer.
Unable to cope with the anxiety, I asked for referral to a urologist but the appointment is months away and finally GP saw how distressed I was and agreed at my request to fast track me. Appointment to cystoscopy is next week, same day as the ultrasound and I am terrified they will find something sinister and don't know how to cope. My risk factors seem to be greater because I dye threads and fabrics (for the last few years, not every week but when I do it's 2 times a week more or less). I am in a state of panic, find it hard to function and am driving my poor husband mad worrying about it. He can't understand why I can't 'shelve' the worry but if only it was that easy!
Anyone else had anything like this, or tested their urine obsessively (well, for the last 2 months anyway!)

well, let's relax and take a breath. Trace epithelial cells in urine are quite common and can be present even in the absence of bacterial contamination. Traces of blood can also be common as well and the fact that you have cystitis could increase the potential. That's the inherent danger in home testing; it's interpreted by lay persons. These tests are merely a guide to provide you with a general screen, not professional diagnosis. Always remember that.

Relax and wait for your cystoscopy. It'll turn out fine. I'll add here that the only thing "sinister" about discovery is the absence of it. Never take early detection of any medical problem as something to avoid due to fear. It's where medicine is making the most tremendous strides these days. That's largely why the home screen tests are so widely available and popular.

You'll be fine.