A very poorly boy

Today is not a good day.....on Tuesday Daniel started with Diahorrea and vomitting, it was bad from the off and he developed a temp to boot. After a day he then started with Tummy cramps that have him in so much pain he is literally rolling around the bed..the doc has been this morning and said they cant figure out what is going on really, it is probably an infection of some sort - he is now yellow too and had lost over 2lbs in weight :( ....they are putting it down for now as the cumilitive effects of the chemo, it has damaged his gut and caused it to swell and inflame, therfore anything that goes in is causing it to spasm giving him the most horric pain, he was started on paracetamol and codine, which wasnt really helping but they have now given him some morphine and he appears more settled, only time will help, doctors think at least a week and once his numbers start to recover he should improve. His tummy is totally resting, he is having no food and only sips of water hence starting the TPN feeds which we hope is just short term.
I know, most of you reading this want to help or say something reasurring but rest assured i dont know how to handle this or what to say any more than you do. This is undoubtidly the hardest time in my life, to see your own child suffer in a way you cant imagine is heart breaking and until such a time comes that we can say "his treatment is over" and "he is well" , i wont settle and every time i hear him cry or see that pained expression on his little face a small part of me dies inside....
Life is cruel.