Childfree people without any siblings, how do you plan care for your elder years?

I (32 F) don't plan to have children, and my current partner (M 45) is totally against them and is not changing his mind. I am okay with my decision but my parents are constantly telling me that since I don't have ANY siblings I will die alone, or worse, I will be having dementia or being sick and nobody will be around to help me because... partners don't stay and even if they do, women usually live longer (let alone that I love more than 10 years older than me men). Chances are that if I get to live by 80 I might break something and I will die in the place I fell starving and thirsty for days. I am gonna "melt"...
Childfree people without any siblings, how do you try to "secure" some care for your elder years?