I have been caring for my mother-in-aw for the past 3 year and just recently my husband was diagnosed with cancer. I can't take care of them both, what should I do?

I just don't have the energy anymore to take care of his mother and neither can he. She is 84 yrs old with CHF and very bad mobility due to arthritis and a huge fear of staying by herself. My 28 yr old daughter has been staying home with her when we are at work and is now very burned out. With my husband now going to start cancer treatments and with his recovery we want to move his mother into a nursing home. There is no money at all to have in home care. His brother is flat against it and has only seen his mother a handful of times in the past 3 yrs and lives 2 1/2 hours away and his sister has visited about 8 times in 3 yrs and lives 40 miles away. We have found a very nice place and want her to be placed before my husband has to start cancer treatment next month. The stress of cancer and taking care of his mother is putting us pretty much over the edge. His mother can not bath herself or wash her own hair. She fell last week and her other kids don't understand why.