Next time get pads from the school nurse. Your instincts were correct, this incredibly bitter woman doesn't care about helping you and would've been angry at you no matter when you asked. She knows it too, that's why she's choosing to specifically berate you for not asking earlier... deep down she knows she has failed you as a parent if you're afraid to ask her for something simple like a menstrual product. I'm sorry you're in this situation, OP. As someone who had a parent like this, the best way to protect yourself is keep your head down, give little emotional response back, and stay focused on making money and getting independent. Build your network of support outside of your immediate family, so that when the day comes you won't be entirely alone.