I cut my father off after a straw-that-broke-the-camel's back event. It was really painful for a year, especially because I had to break through the FOG (Fear Obligation Guilt - especially the bloody Guilt) that had been instilled in me as a daughter but I stayed resolute because I did not want my children to be exposed to him and his meanness and destructive behaviors. I also didn't want to waste any more emotional energy on him myself. The pain disappeared after 1 year and now, 20 years later, I hardly ever think of him and when I do it is with dispassion. I did the cut off without therapy, but think therapy would have helped a lot.
I have NEVER EVER regretted the cut off, it allowed me to give all my energy and time to my children, it let me build a rich peaceful life for me, my H, and them. I now look back and see that what I did was a courageous act that broke the chain of toxicity that had harmed so many people in the past, especially my sister. She had been groomed to be his servant and run after him, constantly seeking validation and love. He treated her horribly, pretty much like your father has treated you.
OP, I agree with @StopStartStop
"Get therapy, these people have been hurting you for years.
Block them - on your phone, on every social media, everywhere.
Keep busy, focusing on yourself and your children.
Move if you can, but otherwise keep your mind closed to your dad and co."
I'd add to that, watch out for the flying monkeys in the form of your brothers, their wives, other relatives, family friends, your father's gf etc. They'll come out in droves once they realize that they will have to step up for vicious old daddy. Block them all now.
Susan Forward's book "Toxic Parents" might be a good read for you. Her other book "Toxic In Laws" is also good, including for the adult children of toxic parents.