Your mother has; A tendency to envy and delusion; Have menopause; There is also suggestibility, and there may be some personality disorders or mental problems.
Objectively speaking, the above situation is not easy to solve. Taking medicine may solve some superficial problems, but it can't solve the fundamental problems. So, I give you this advice;
Let your mother and your father believe in Christianity or Buddhism together. Let your mother tell the preacher about her inner troubles, or when your mother is religious, there will be an answer in the doctrine.