Hey Trip. I'm sorry you're going through such a tough time. Living with the 'rents can be hard even in the best of circumstances. I don't have any super great advice for you, but perhaps I can try to lend a little perspective?
I realize that all of what I'm about to say is really easy for me to say because I don't have to live with the bully, but my own father passed away 6 or 7 years ago. From the age of about 12 or so I was getting in literal knock-down drag-out fights with him, yet I still lament the fact that he's gone. For all of his many flaws he was still my father who, very deep down underneath all the insanity and cruelty, loved me very much. Do you think your father still loves you, somewhere underneath all the BS?
I could be completely wrong, but it kinda seems to me like perhaps your father is dealing with his own personal hell, and sometimes one of the ways someone deals with such a thing is to spread the misery ("Misery loves company"). Certainly your father is not perfect, none of us are. Though admitting this can be, at times, more than we're prepared to handle. "If I'm not perfect then just how much of any of this is my fault?" It's a scary prospect.
Perhaps I'm way off-base here and if so I'm sorry, but...I gather that you're "out" to your dad, right? Do you think he's going through the stages of grief at the "loss" of his child, or who he thought that child was?
Being a cishet white man can often come with some pretty rigid world views that can be quite difficult to let go of. Regardless of where he's at mentally and emotionally, the only thing you can control is you. It's up to you how you respond to him, if you escalate the situation or allow yourself to become a victim, be the rational adult or the petulant child, or any of the other potential ways you could react to his instigating.
Not everyone can be reached, but some can. While we need to limit the harm that others do we also need to realize that harshly judging them, especially to their faces, is unhelpful at best and potentially damaging at worst. If you try to inflict pain then they're going to go on the defensive. But you -may- be able to reach them with love and compassion.
Show your father that you're still his child, though you may be an adult (or close enough for all intensive porpoises) and that you care for him and how his actions are harming you. If he absolutely refuses to be reached, to work with you to make both of your lives better, then figuratively wall yourself off from him. Limit the emotional damage he can do, don't allow him to provoke you into an escalating situation. Get your own life in order so that you can remove him from it as quickly as possible.
I'd recommend, even in that case, that you do not completely burn the bridge with him. At least not in a reactionary "I'll show him!" sort of way. It really sounds to me like deep down in there somewhere he loves you and is having a hard time with things, and perhaps some day in the future, as he mellows with age, he may come to you wanting to fix the relationship.
Or maybe he's just a grade-A ->-bleeped-<- who seeks only to harm others and will never be a decent human being, that's up to you to judge. But no matter what you've got people that care about you here at Susan's. Please message me if you'd like to talk more or need a friend.
<3
