I'm scared to go NC with my family in fear of being all alone with no support system

I want to go NC or atleast LC with my family but I don't have anyone else in my life except a romantic partner and we are childfree. In the long term it sounds like a bad idea because what if I need some sort of help? What if my romantic partner betrays or abandons me if I get terminally ill or something. I have all sorts of scary scenarios play in my head where I am all alone on the streets or something.

I could use some insight