What do we do with our disabled senior (and my mother-in-law) who is bored and disinterested in everything?

No matter what we do, it's complaints all day and every day about everything. We have had her checked out by the doctors over and over in the past few months. She does not want to eat and complains about all her food. She is not sleeping at night anymore - worrying about things she shouldn't even be thinking about; always wears a Depends but goes to the bathroom constantly and all night. Is Arthritic and complains about pain, pain and more pain; complains that her medication and supplements do not work and is starting to refuse them; does not even read the newspaper; is overweight and MOST inactive; watches 2 game shows on TV in the morning and one 2 in the evening and lays in bed almost the rest of the day; talks to her friends on the phone in the morning however, once that is done she gets bored with the TV; she used used to be an avid baseball and soccer fan - hasn't watched any games in months; expects us to sit with her all day and gets angry if we don't. I think she need to be seen by a psychologist but there is no way this will happen - it is costly and there is no-one to take her. This is a very difficult situation. We are at our wit's end and do not know what to do.