Very fast vascular dementia slide after 6+ years...Now what?

Mom is 76. Stroke at 70. Developed Epilepsy at 74. Doing fairly well until hypothermic episode (6 mos ago) when body temp went to 89.9. Now only is 92-95, max. Seizures became monthly, then weekly, each one taking more memory. Just last weekend she was talking, although appetite decreased to a few spoons of soup a day about two weeks ago. Then just refused to get out of bed for 4 days. Last weekend was very agitated with her nursing facility staff, yelling obscenities I've never heard from her. This week didn't eat 3 of 5 days, stopped communicating, just stares. Maybe out of bed 30 mins a day. Hospice is involved but so is the facility and me as POA, I have no clue what's up. She stares with her head down and drools. Very upsetting for me. Developed some type of cough I've never heard two days ago. She is DNR. She always told me she wanted me with her if she passed. She's 20 miles from me. I'm there every day but can't stay ALL the time but would if i knew her condition. Months? Weeks? Days? I've been with her every step from Day One, the stroke, almost 7 years. I've lost 2 jobs. She's just more important. Went from walking, to using Walker, then wheelchair bound 3 years now. I've not missed a monthly care team meeting ever. My gut says something is very wrong, but when I call, she's "sleeping comfortably." Went from cussing up a storm last Sunday to now not saying a word. No bowel movement in 4 days. Low blood pressures and pulse. I don't know when I should start staying with her all night. I just restlessly sleep and check my phone several times a night. So tired and burned out--almost 7 Years now. If I break my final promise to her, to be with her when she passes, I will be devastated. Can a person live a good amount of time on just sips of water and soup broth? It's at least something...