Xenia,
Your post triggers memories for those who have or are making this journey with a loved one. It occurred me that I too was dying as I companioned my former partner to her death. The only difference was that my death was a metaphorical one, hers was physical and real.
I felt selfish at times and wanted to cry with her, but soon realized that this was not about me, not yet. It was I who had to provide the comfort and the quiet space to pass. So I had to have a support system for myself - these were a close friend and a counselor at Hospice. I also arranged for daily respite so i could get out to walk, ride my bike, go to yoga.
Self-care for the caregiver is very, very important. It will help you be present in the moments when he needs you the most, and those days will come. Now is the time to put the things in place that will sustain you later. Don't let any denial on his part dissuade you.
Your posts about the journey are good to read.
Dale