I've had those nights-spending hours watching the Weather Channel-which usually puts me to sleep-and that didn't even do the trick.
Make sure you're not ingesting too much caffeine in the evening; also try not eating past 8 pm. I try not to drink too much alcohol, too, because it will cause night wakefulness. I have also read that exercise in the evening, or any strenuous activity, can make it more difficult to get sleep.
And read something boring-that often helps.

Sounds like you're under a lot of stress, too. Try to do some quiet time each day-even 10 minutes-to just let the stress pass through you. Many of us have trouble dealing with stressors and it can exacerbate everything going on.

Prayers for you and your grandmother-"Ask, and you will receive...knock, and the door will be opened for you." Or something like that...I believe that prayers are answered...especially if we concentrate also on things in our lives we are grateful for...I list 5 things every night before I go to bed of what I experienced that day or people in my life that I am grateful for. Helps me go to sleep peacefully.

I pray for success in helping your grandma, and for sleepful rest and peace for you