I'm sorry for all this chaos going on in your house. Are there any visible rashes or bites all these times your mother thought there were bugs? Rinsing her eyes with borax solution is dangerous and putting it on bird/pet is dangerous too. She needs to tell all this to her doctor and tell her this every time she complains. This sounds like a serious issue that needs a doctors care. How does your mother support herself? I feel if this was menopause it would have showed itself earlier. You may have to make the tough decision to save yourself and move out.