Breaking Bad

One.

Horrifying. I once needed surgery for a cyst on my back. I couldn't sit up and I had to fast for the surgery. No food no water from 9pm the previous night, till 7am when it was supposed to be. However the surgery was delayed and I was put in the childrens ward. I couldn't sleep because of the pain, so I tried to bear with it thinking it would only be an hour or so.

The surgery was delayed by 15 hours, and they insisted it would be "a few more minutes" each time I asked for food or water. I went 25-ish hours without food or water, I fainted from dehydration, that's when they finally treated me.

No I did not ever get the surgery. I went to many doctors begging for alternatives, I got a course of very strong antibiotics and was instructed to take saltwater baths until the cyst popped, then disinfect with the provided solution and take the provided antibiotics. It worked.

TLDR: I went to be treated, several of the surgeons were off that day, I was left without food or water for 25 hours, then it turned out I didn't even need surgery.

The NHS are notorious for putting you on waiting list after waiting list, instead of helping you ASAP

Walt starts cooking meth because he can't afford the treatment, the wording may be wrong, but the idea is correct. If he had free healthcare he wouldn't start making meth.

cancer going untreated for a long period of time is partly what makes it so deadly

I've seem multiple people catch it, and get it treated right away. One of them being my mother. She caught it fairly early once. Beat it. All the yearly tests and mammograms..... and she caught it herself again. The tests never showed up positive and once again after she caught it. She was treated and sent home with a clean bill of health. All the blood work and test after that. Never told us that it came back again in her and two months later she passed away. You don't cure cancer. You live with it for as long as it decides to let you.

No he doesn't, he has an operations and a round of chemo then goes into remission

Every synopsis I have ever read about the show describes it as inoperable or terminal. Here is IMBDs:
"Informed he has terminal cancer, an underachieving chemistry genius turned high school teacher uses his expertise to secretly provide for his family by producing the world's highest quality crystal meth."
If the show decided to change direction from how it started, oh well. My point still stands. If you're told you have inoperable or terminal cancer, especially lung cancer, its a death sentence anywhere.