She's Killin Me Here ... Could Use Some Tips on Living With the Elderly

Leanna, Your situation is all to common today. Thats why they make sitcoms like Fraiser, King Of Queens, Raising Hope. These lead us to believe its a managable situation. You are one of the many who have learned the hard way that in real life this situation is not managable and is far from comical.
I dont have words of support nor can I guide you to the support you need. I do hope and pray you find it.