Thank you for explaining. Yes, I only realized this month just how bad her mental problems are. Today I learned the term "financial incest" which was something our parents did and "money anxiety disorder" which my sister definitely has. The parents had more influence on my sister because she was really naiive and even helped them commit crimes like medical fraud to sell cancer cures. So now she imitates our stepfather's actions as an adult which includes overspending and then blaming me for it.

Most of her meltdowns were over money until the last few years when everyday things started to piss her off as well. I was just thinking about an incident when we were in collage. We lost the tweezers we shared and after a month without tweezers, I bought some new ones for $1.39. My sister was ok with the purchase until she found our old tweezers between the couch cushions. Then she started yelling at me for having spent the $1.39 and when I tried to walk away, she came after me and kicked me. Today I decided I'm not going to let her bad temper stop me spending money on things that I need. I bought something for $15 without her knowing and I'm a bit anxious about when she finds out, but I'm not going to let it stop me anymore.