Caring for Parents

I suffer with severe PTSD due to my childood, I've been in and out of hospital many times for suicidal attempts. My parents verbally, mentally, emotionally and physically abused me. I have no love or nurturing as a child, I was neglected, putdown and abused. I recently moved back to my home country to support my siblings with the rapid decline of our parents health. My dad is in stage 5 kidney failure ( he chose not to have kidney dialysis) and my mum is in stage 5 dementia. I will also inform you that my dad is an extremely controlling and narcissistic man. He trys to blacksmail us and succeeds with mum. Mum has always bowed down to him and has never had her own voice. I renently went with my sister to visit them and dad never asked how we were, he only complained about himself, his pains and also when my mum spoke told her to stop talking because she doesnt know what she is talking about. He then turns to my sister and I asking about shopping we bought for him ( no thank you) and demand of what he wants us to do for him while were there. Im holding lots of anger and hate towards my parents and wish to have nothing to do with them but feeling so guilty for it. Is this wrong of me.