Sorry to hear about your experience. And my condolences for your father. Having to attend an occasion like a funeral with people that treat you like shit cant be easy and, as you've seen, JWs will just jump at the chance to make you feel worthless and guilty even at a funeral. It's what they do.
I don't think I will participate in any way when the inevitable happens. I'm dead to them, they're dead to me.
I wont be going to my mums funeral when she croaks it. There's very few JW family members that I would go for. One of my sisters and maybe my JW uncles but I just know I'd be glared at and on the receiving end of passive aggressive behaviour.