I dont wanna accept that my parents won’t be around forever.

My dads girlfriend a couple weeks ago made me cry HARD when she told me off about how I’m treating my dad and she flat told me bluntly in my face that my parents won’t be around forever and I need to start helping out more and I’m very young. Plus I need to start thinking about getting a job and working on getting my own place soon because daddy will not be along for long and I need to stop being a little bitch to him. I told her I’m autistic and go easy on me but she refuses and said stop using aspergers as an excuse and I am very smart and capable and I am not a child anymore. I just turn 18 last month.
She made me cry and the thought got stuck on my head about what she said. My dad is going to be 65 next year. My mom will be 55.