I understand you are disappointed that the scan result is not what you were expecting, but you're being quite melodramatic and assuming you won't be treated.
I need a full knee replacement, can't actually straighten the knee. I was hopeful the surgeon could clean up the torn, frayed cartilage mess but he said there's a 30% chance he'd make it worse, so we agreed that wasn't a good idea. I'm too young for a replacement due to how long they last (first replacement 20 yrs, second 10 yrs and rarely can they do a third as they run out of bone). After 2 years I decided we'd do the knee anyway as it was impacting too much. However my hips are shot so need to do those first. Left done in Jan, right will be done in Nov. Hip pain refers to to back and knees so I'm optimistic the knee may be able to keep going for a bit.
I'm not trying to compete with you on pain, just explain where I'm at so you know I understand the pain and the impact it has on your life.
Pain needs to be managed. For knee pain, as noted by other posters, knee braces and the knitted supports actually help more than you think they would. Takes a bit of trial and error to find the ones that work for you and having a selection is good as what gives relief can vary depending on what's feeling aggravated that day.
Other management is a lovely weighted, heating pad I got from Amazon; a tens machine - absolutely amazing relief using that; when sleeping using a pillow between knees or behind the knee if sleeping on my back.
I take diclofenac, which is the generic name for voltaren. It was even used as part of my hip replacement pain management. It's great and makes a noticeable difference. In Australia you can get 25mg over the counter, but it's much cheaper with a script.
Finally, I work with an exercise physiologist. Only thing that keeps me mobile. For me, the pain at the back of the knee is caused by two nasty little ligaments. Hideous to be worked on, but the outcome is worth it. Overall, working on your muscle strength is the best way to suppirt and stabilise the knee.
Don't cancel your consultant appointment. See them, explain the pain is restricting your daily life and you have to stop doing activities because of it. If it impacts your sleep etc, then say that too.
There is nothing worse than that constant, deep unrelenting pain that you cannot get away from. You can't sleep as there is literally no position that is pain free.