I have been the primary caretaker for my 89-year-old mother. She has been on hospice for 2 1/2 years now with "end stage" heart failure. 2 weeks ago her BP was 95/51 and they stopped her Lisinopril. BP is back up to 122/61, but her feet and ankles are swelling terribly. My DH and I are supposed to leave for 3 days to "relax", but what if she dies while I'm gone? Do I take the chance and go and worry the whole time or stay home and be angry because once again I'm left to do it all. I have 4 siblings and no help.
Take your vacation. I say goodbye to my mom at each visit as though it might be the last.
Go. Recharge. Come back and be better able to deal with what faces you then.