My brother is in his 40s and has been diagnosed with neuroendocrine cancer which is secondary in his liver and is receiving the relevant treatment.

We haven't actually spoken in many years, so this feels like a complicated situation.

My mother is a very pessimistic person and seems to spend her days crying about the situation and she also cries in front of him and is always talking about "whatever time he has left". 
 

His wife seems to also be quite negative about it but I appreciate that I am not living with this and am not around him through treatments or anything.  However, I do feel that the circle of negativity around him, especially as he's also focused on the fact he's going to die, is really not helping.  It feels like they're all feeding off each other which I feel isn't helping.

I have suggested they seek counselling and help but none of them have done anything about it, my mum doesn't feel she needs help.  My dad, I feel, is stuck trying hard to hold everyone up.

The talk has already turned to him not being around much longer and now his wife is talking about me going to see him (because he's too stubborn) "before he dies"!

am I being unreasonable to feel like they should seek help, to stop feeding off each other's sadness (especially around him)?  There doesn't seem to be anyone who is there to be "normal".  
 

I appreciate all of this is easy for me to write as I am not in his shoes, but surely this is just exacerbating the situation? 
 

I don't really know where to turn to seek help in order to guide them as I'm a little bit removed?