It seems to psychosis induced Cibophobia. It needs to be treated asap otherwise it may get complicated. It can be well treated with counseling sessions and medication if required.

Hello, As you said your mom is having such issues, i would request you to take an online consultation from a psychologist. And You should first try to communicate to her. Communication plays a vital role for understanding things

I understand you really love your mother. To understand the problem ahe need to consult. You can book online session for your mother..

Hi... Please consult a Psychiatrist. You can go alone or with her. Your mother appears to be suffering from a disorder. Psychiatrists will diagnose and prescribe medication. Psychiatrist will also guide you how to administer medication as well. Once her condition becomes better with medication and she becomes open to Therapy/Counselling, you can consult a Psychologist.

Googling for health-related information in an obsessive manner and following what has been found from the search even more obsessively may be stemming out of anxiety - which may be connected more with  illness anxiety disorder (old name being hypochondria). In your mother's case, her wellbeing is more important than the label that can be fixed onto her condition. Even though I don't know if you will succeed in doing so, I would suggest you to get her some help in managing her anxiety, preferably from a psychiatrist. Visiting a psychiatrist is often considered as taboo. Yet you may have to get her professional help somehow because of the possibility of her condition worsening with the passage of time. If you find reaching a psychiatrist difficult, you may even try to get her help / guidance from a psychologist.

She probably is suffering from hypochondriasis/health anxiety. Talking to her about her thoughts and feelings and making her realise that you always have her back and that she’s respected and appreciated would provide first aid. But you would definitely need to take therapy for her that would provide relief from anxiety and help her with coping skills