Hi there.  3am is a dreadful time for anyone with worries.  I cannot give you a great deal of practical help but I wanted to say hello.  Don't panic about your mum having a meltdown - there is a limit to how strong anyone can be - certainly not all of the time.  Has your mum got close friends she would like to see?  Or other family members who are closer than your siblings?    Ask your mum what she would like to do, who she would like to see.  I think you are wise to look after your own well-being too.  Is your mum good friends with any of your neighbours - I have helped care for a couple of close neighbours who were terminally ill - one with cancer - they were used to me and my ways and vice versa.  One of them said he was pleased that I talked to him just as I had always done; but it was a bit easier for me as he wasn't a member of my family.  I would also mention the MacMillan nursing service who seem to be very good at supporting cancer patients in their home.

With my very best wishes.