My mom is 78 years old and she had her leg amputated several years ago. My brother that is now 60 is living with her. She can no longer bathe herself or use the commode. she no longer gets out of bed. We have told our brother we will support him in getting her into a nursing home. He is diabetic and has other health issues as well.
You said that you didn't know where to start the process. The process of getting her into a nursing home? Tour a few, pick one you like, and they'll help you get the ball rolling.
Your mom's life is liable to improve in a nursing home. They'll get her up, she'll get to go to activities, there are people around all the time. It would probably be better for her than laying in a bed all day with nothing to do and no outside stimulation.