How do I get my grandmother to go to the doctor to get help?

My grandmother is in her mid seventies, and she is increasingly loosing her ability to act in a normal manner. For example, she wears Poise pads instead of going to the bathroom, urinates in trash cans and spills it in the carpet, blaming it on the dog. She cries over deaths of people she doesn't know because she says that she is afraid that they didn't go to heaven. She asks me to log onto the internet and look up obituaries of people she grew up with all of the time. She is afraid of everything and cries at the drop of a hat. Every time she hears a bit of gossip or a tale about someone she knows, she repeats it, but exaggerates the truth. She seems to be miserable and frightened all of the time, and just living in this limbo where she is afraid to live but scared to die. She appears overall healthy, but she tells everyone that she is on her last leg, health-wise. For example, she received a pace maker a year ago, and she tells my daughter (her great granddaughter), that she can't walk to the park because her heart will stop (even though my mother was there with her at the doctor's office when he told her that she needs to walk). She tells everyone that her doctor told her that she can't eat gluten, but doesn't know what gluten is. She can't remember how to use a computer even though she was an accountant for years for a company. She can't remember how to turn the tv on/off and how to put a dvd in it. My four-year old can do some of these things. I am scared that she is battling the early stages of Alzheimer's. Her mother passed away at the age of 91 after battling the disease for years. I think that she is secretly afraid that this is her problem. She was her mother's main care giver, and watched her go from an independent, strong woman to a bed-ridden, shadow of her former self. It affected her greatly. I don't know how to do it right now, but I need to get her to the doctor to get a doctor's opinion. Her feelings get hurt all of the time because I don't trust her with normal tasks like cooking (she forgot the burner cover was on and almost started a fire), and with my children (she placed my one-year-old who can't walk yet on a bed and let her roll off). I love her, and I don't want to cause her more pain. She reacts very poorly to any sort of help. When I confronted her about spilling urine from the trash can, she just got treary eyed and really quiet. I was as nice as possible. Oh, I think I need help. Any suggestions on how to get her to at least go to a doctor to talk about it? Thanks.