This is the first time I've posted on your thread but have been following. Do call the nurses out whenever you need them - I remember with my mom we had a record of having them out three times in a night for various reasons - they were brilliant.
Is your BiL with you at the moment too?
I posted this on another thread but my sister died this year - she was young (but not as young as your DH) and she went into the hospice. The staff said to get family in as they thought it was likely she was nearing the end but she held on for another 3 days or so - the staff were surprised and felt that despite the extent of her cancer - other parts of her body were still young, strong and so it felt (obviously we'll never know) that her youth and strength were fighting it till the very end (if you see what I mean). She also had times when she appeared agitated - whilst we knew that this wasn't really affecting her it was upsetting to see and whilst one Dr was a bit dismissive of our concern another acknowledged that their role is supporting both the patient and the family and tweaked medication so the agitation disappeared.
On her last night after we ended up dimming the lights and putting on one of her favourite albums (she'd not been awake for a few days by then) and she gently passed away a few hours later. Obviously it may have been all coincidence but it helped us to think that it had "helped" in some way - in soothing her - as I understand hearing is one of the last senses to fail/go
I say all of this just so you're aware in case this phase lasts longer than you're anticipating as it can be so emotionally difficult, the caring, the grieving, the constant watching and guessing.
Also - and as ever you must do what is right for you - but with our mom we found a Macmillan sitter/carer a great help - not just because it gave us a chance to sleep but also because if I'm honest I felt that friends and others were getting a chance to "be" with mom whereas we were "being" the carers. Now there is a great honour/love in having that role but I felt in that circumstance it was getting in the way of being her daughter - just for a little while longer. So if you do decide to ask for carers support please don't think you're offloading a duty of honour/love for your DH to someone else but more that your carving out some space to be his DW.
keeping you in my thoughts [flower]