Hang on its going to be a bumpy ride (again)
I am so sorry to hear about your brothers health problems. I want you to remember back in early-mid grief. Remember when we doubted our health, those around us? It was almost a clarity of paranoia. Of what could happen in the bat of an eye. Having those sick around us forces us to remember the very tragedy that we went through and brings the awful possibility of it happening again.
You will be strong for your brother though the feelings of helplessness return with a vengence. We relive the very thing that changed our life forever don't we?
Don't go to work. Figure out what you need to do and take control of the situation until you have the time to break down.
Again I am soooo sorry that you need to feel so helpless and relive the worst time of your life. Anticipation and worry really do bring out our worst fears and strength we did not think ourselves capable.
Hang in there Jules. Thinking of you...