In those last 4 days when I knew Chris was actively dying I slept in the lounge room with him on his recliner chair. I say slept, but it was more I would doze off for an hour or so, check on him, doze off again. Day and night. Yep it was tiring but I couldn't leave the room and sleep in my bed.
Chris had been sleeping apart from me for about 6 months full time by then, and had not slept a full night in our bed since a month or so after diagnosis because he had too much pain in our bed. (he was gone only 11 months after diagnosis).
I would say, just let yourself do what you feel you need to do.
PALS often wait for the room to be empty or for you to be asleep many people say.
Many PALS do pass in their sleep, either suddenly or in a slow active decline.
My Chris passed around 2am. Around 11pm the night before I used a homeopathic remedy prescribed for him to help alleviate the fear of dying. I mixed it with water and washed his face and hands with it so it could be absorbed through the skin and I told him many things of my love for him and my sorrow at this monster attacking him. I told him that he was in a serious state and he was not going to come out of it and bounce back and that it was OK to let go.
I kind of walked and paced, and lay on the recliner and held his hand and talked to him on and off the next few hours. His breathing began to slow (rather than the rapid very shallow breathing of the past few days) and he did not acknowledge me, but he simply slipped away very peacefully.
He was asleep, or at least not actually conscious, when he passed. He never had bipap (he never wanted one), but even if he had a bipap then he would have passed.
So all I am saying is, that if you would feel better being with him, can you rig up something to rest one, even if you are not sleeping properly, that is in the room with him?
I would like you to know that I am holding your hand. The beautiful people here, and in another CALS group I am a member of, held my hand all the way through. Just keep giving him comfort care, let him know you love him too, and do what feels right.
I kept beautiful candles burning and lovely music playing, I found the atmosphere this created helped us both feel very peaceful, even if the worst thing was happening, there was a lot of peace.
I hope you can create a place of peace for both of you as you work through this. I hope I can be looked after in such a way when it is my time to go.