You are brave, Snowwhite!
Well, allow me to show how I see it (because we humans are seen same way, as toxic, from other´s side).
Any time, your Dad would pass away and, the blood is nothing compared to real friendship bonds, no matter what your dad might say. Do you love the others as yourself? If so, you are honoring GOD, not the world an its limits.
Al tend to be troublemakers and seldom we are trobleshooters: Where are you in that? Solving or messing thigs up? (I guess in the right WAY: Jesus).
Your are not going insane, that´s another insanity. If you are strong enough, you can dealt with that (and more) but, what are you seeking there? Will you keep it up, once you got it? (Just your decision).
I have heard of families like that. Mine is not that sort and, as far as I remember, I was the toxic part (and I know my limitations) and, since I still serving some of my family, I´m not so poisonous (as I was, in my childhood) so I guess you would succeed if you willingly wnat to lease your loving drives and family bonds: Just follow Jesus.
Jesus had toxic brothers. They disbelived Him and wnated to hurt Him (read His account and sayings in)
(*) so, any day, you would enjoy the good deeds you could plan for those you like.
(*)
Joh 7:3 So Jesus' brothers told him, "Leave this place, and go to Judea so that your disciples can see the things that you're doing.
Joh 7:4
No one does things secretly when he wants to be known publicly. If you do these things, you should let the world see you."
Joh 7:5
Even his brothers didn't believe in him.
Joh 7:6 Jesus told them, "Now is not the right time for me to go.
Any time is right for you.