Not sure what do to with my mother she is 69 years old and seems to be starting forgetfulness and very angery?

SHE COMES TO MY HOUSE AND DOESN'T REMEMBER BEING HERE , WHEN I TALK TO HER HER TONE IS AWFUL AND NASTY , SHE GETS SO MANY THINGS CONFUSED AND I'M NOT SURE WHAT TO DO SHE WON'T LET ME HELP HER IN ANY WAY . IS THERE HELP I CAN GET HER I'M VERY WORRIED SHE MIGHT HURT HERSELF ON ACCIDENT OR HURT SOMEONE ?