Very well said Goosey!
I think that determination and a good sense of humour are extremely helpful during 'challenging times'.
A 'therapeutic vent' can do the world of good, but as you say, not all people are blessed with a 'robust' mindset (a counsellor friend of mine called them 'psychic vampires' - you can feel their negativity draining your mental energy).
I underwent radiotherapy for breast cancer a couple of years ago (I was extremely lucky to find it so early), and tried to be supportive of a chap I used to travel to the hospital with (prostate cancer). I'm afraid to say that I now avoid getting into conversation with him, as helpful suggestions fall on deaf ears, and I find the negativity exhausting.
As my Gran used to say "count your blessings".