You were right to write the letter, pardon the pun. I'll give you two examples I've experienced throughout my lifetime.
1) My dad had prostate cancer and passed away in 2016. A good friend of mum's kept inferring that we hadn't done enough to "catch" the cancer in time. About a year after he died, she still kept insinuating that it shouldn't have happened. She insisted that if it were her husband, she would have done things a bit differently. Like what? Dad attended all the appointments, got all the treatments, saw all the doctors. Sometimes, things are outside of our control. Even during dad's chemo, she kept insisting we be socialising, despite dad's compromised immune system. She was a nurse. I ended up doing a similar thing and writing a letter to her pointing out how ridiculous her attitude was and to respect our right to grieve instead of the constant pressure to "get back on the horse" so to speak. She was a good friend of mum's for over 40 years. I simply held the mirror up to her face. Apparently her ego is more important than her friendship with mum. We haven't seen them or spoken since. I should add that despite all her well-meaning advice, not once did she ever visit us at home during dad's dying days, and not once did she visit him in hospital. Actions speak louder than words.
2) Mum got bladder cancer a few years ago. When my brother first found out, he started mocking her for having an overactive bladder, the 1st symptom. Then when mum pleaded for his support, his reply was "I've got my own family to worry about" . It virtually ripped mum's heart out. I had several mental breakdowns as a result of the uncertainty, stress, especially with dad gone. Once again, he mocked me and made fun of the fact I was "struggling". Several years later, and 1 or 2 social visist (Christmas, Easter and I think mother's day), and he is at least on talking terms with mum again. I'm currently seeing a psych monthly, partly due to the betrayal, partly because of the stress of mum's illness. But the fact is that in both our darkest hours, he and his wife simply went cold. They turned their backs on us and made up all sorts of excuses as to why. So mum was upset twice. Once from the cancer, and a 2nd time from the utter betrayal of her eldest son.
Moral of the story. It's not you. You have been touched by an illness that threatens your mortality and other people run scared. The fact is, until you get the treatment and it has been successful, you don't actually know if it is "curable". Ignorance suggests that everything is "treatable". It doesn't mean that it is curable. There is a big difference, which your friend obviously doesn't understand. It is this uncertainty which causes stress, anxiety, depression. The truth is, you don't really know people, friends or family, until such a crisis hits. Then you soon figure out the depths of their character.
