While I am not a caregiver for anyone, I am a hospice volunteer and so have contact with the families and caregivers on a daily basis. I can see when the caregivers are starting to feel the pressure of the demands of their situation and I step in and do what I can. 

The most important advice I can offer is to allow yourself to have a break from the situation, even if only a few hours. Hire a sitter to come, or if money is tight, perhaps ask a friend or neighbor if they would come sit. Even something as simple as getting a change of scenery, treating yourself to a mani/pedi, makes such a world of difference in your outlook. And DO NOT FEEL GUILTY for getting overwhelmed with the situation. It is a demanding job physically and emotionally, and the best thing you can do is take care of yourself first and foremost. If you don't, you won't be any good to anybody! 

Susan