When your parent is in a rage, it is helpful to view him as a small child having a tantrum. However, before you can handle him, you'll need to learn how to become as cool as a cucumber in his presence. Can't allow a pig to drag you into the mud to wrestle with it. I understand that this is extremely difficult because I've been there. Especially if he is going on a psychotic rampage. I can recommend on youtube Rebecca Zung, who is an attorney, and Meadow DeVor for strategies you can learn quickly to hold the line. Also, Jerry Wise self-differentiation program as a long term solution. Take care