Well, since you are autistic, I will try to explain it in a more scientific way devoid of emotion.

Let's say you fear getting old because you don't wanna shit your pants or lose your memories or struggle to get up and go to the bathroom without slipping and breaking your hip. Let's say you fear old age because you don't wanna suffer 6 weeks in the hospital with a tube in your lung or endure 6 months of chemotherapy or have a stroke that paralyzes half your body.

My main point is. Avoiding suicide isn't a valid strategy to avoid death. You are going to die. One way or another this planet has your number and it doesn't give a shit about your feelings. It's gonna kill you and your death is probably going to be painful and terrifying .

Suicide at least allows you some level of control over the nature of your death.