My husband died from a heart attack in March last year. It was completely out of the blue. He went to sleep and didn't wake up. We were due to care for our 10 month old granddaughter for 3 days in May whilst her parents had a short UK break.
I became paranoid about becoming incapacitated whilst caring for her on my own, I was a fit 71 at the time but then my husband was a pretty fit 73 year old when he died.
Fortunately, I had a good friend who was happy to come and help me. We all, baby included, had a lovely few days together.
Maybe you can find a friend or relative to help you?
Since my husband's death, I have also had my twin grandsons to stay with me. As they are 10 years old, I was able to chat with them, with parental permission, about what to do if granny is unwell. We devised a plan and I typed it up. It now sits in a drawer by the telephone.