Hi Kayleen
Lots of deep breaths and self-hugs and permission to cry etc. Not sure if you're aware of it - but google the 7 stages of grief - extremely helpful because although it doesn't change the situation it does help us change our thinking, or more specifically our thoughts - until we get to a place of acceptance. But that said, we may fluctuate and still on some days go back to anger or denial etc.
Also a book called "the reality slap" is very good and another one my brilliant oncologist recommended is 'Smile or Die" - which explores the pros and cons of positive psychology - the bottom line being that IF you spend a day sobbing - it will not add to the cancer spreading - this is SO important to understand and internalise because vulnerability is here to stay!
Re chemo mouth - sorry - not sure here because I'm on targeted chemo and only get ulcers. Mouth wash???
Lots of self-cuddles and revisit your bucket list if it is buried there somewhere in your brain..... and on another day even consider what your legacy may be? This can help with the 'here and now' and also the longer term focus despite zero certainty.
Hope that helps a little :)