Narcissistic mother and father disinheriting child they adopted as a baby for the reason that they “owe her nothing”. Any advice?

Dinzel here from Australia. Sorry I cannot find my account. I am alone and ill in Australian bush. Very wealthy parents told me last year they were disinheriting me because I was lucky they adopted me in Ireland at age 4 months in 1957. Narc Mum has always been cruel to me. There could be dementia involved now also but she knows things such as exactly
how much my Disability Pension from Welfare is. She told me they got
me to replace a little girl they had lost the year before and even changed my first name to that of their deceased child. 8 years later a male child was born to them. My Mum was ecstatic as she is Italian and boys seem to mean the world to them. I posted here before that he has never worked except as a drug dealer and was questioned. Many years ago, from Thailand, he took their entire term deposits although my mother agreed to it. They have even posted bail for him. 6 years ago he returned and made himself their Government paid carer, although at that time they did not need one. They have for at least the last 6 to
8 months and he has also
rung me and said he deserves their houses (worth well over a million dollars) and that I would be a prostitute if they had not adopted me. I
loved my parents greatly, particularly my father. At 4 years of age, my mother broke my arm. I can remember the pain. I was sworn to silence. After a couple of months, she took me to an Infant Welfare Clinic in Australia. Little was ever done. I am 1200 miles from them in Australia and have no husband or children. Once was married but marred by domestic violence. I once had a good job and have two University degrees which they told their whole family about as supposedly I was the first one in the entire extended family to acquire this. Everyone but myself knew I was adopted. As I have Cancer which I hope is improving, I have a Colostomy Bag. This has disgusted them. I used to ring them twice daily and visit twice a year. No longer allowed to visit and phone calls unwelcome. I believe the brother has somehow brainwashed them as they as in their early nineties. Narcissism is also involved. I am shattered that they will treat me like this. I was sent to a poor high school and my mother would not allow me to wash often. I was a little blonde girl whereas the child I was supposed to replace was very dark. My mother resented my appearance and did her best to ruin it by dressing me in old clothes and not allowing washing. The brother was sent to a Private School and later expelled. I am hurt that they told me so late and also about the disinheriting and disowning. I could not find my previous post so made another. Any advice greatly appreciated. Thank you.