Hi
Your father comes across as having traits of a psychopath, seems unempathetic and cold. Especially when you describe him putting a gun to your sister's head (alarm bells ringing!). Also youi said he tried to kill you and you feel guilty?! Seems very irrational on your part to carry such guilt. But it is natural for women to carry guilt which can be irrational. I suggestt you see a therapist to talk this over.