What should I do with my mother who rejects interpretations of the Quran, relies on her own linguistic analysis to interpret verses, becomes extremely angry when I try to correct her understanding, wants to convince me of her views, and is also becoming more isolated and experiencing increased intrusive thoughts?

Your mother is to be commended for her eagerness to understand the Qur’an, but her statement that the Qur’an is self-explanatory contradicts her recourse to the internet to understand unfamiliar words. It is necessary to refer to people of knowledge because foreignness has become widespread and people have moved away from proper language. Knowing the reasons for revelation (Asbab al-Nuzul) and the contextual clues is essential for understanding the Book of Allah; otherwise, many verses would be interpreted incorrectly, as innovators (Ahl al-Bid'ah) have done. Allah has commanded us to refer to people of knowledge. Despite the presence of errors in some interpretations (tafasir), it is not permissible to reject them entirely. Rather, one should choose what is closest and most in agreement with the Sunnah and safest from the Isra'iliyyat (Biblical traditions).