I relate to this.

not for the same reasons as you, (I am still pretty young), for me it's a case of losing too many years and not being able to get them back.

I have this fear that 1 day, when I'm old, and looking back on my life, all I will see is wasteland- empty and abandoned, and before any of that comes true (it all ready is), my life needs to end- I could go on living, sure, but I think to go on living you need to have at least something in mind- something to work towards, I don't have that- and I would rather die than continue on this road of trying new things that just lead to more unhappyness and not being comfortable with my life situation.

I've accepted that I'll never be able to work, and I'll never be a theme park engineer, that's fine- just, when you don't know what to do with yourself and when nothing you try brings you any happyness at all, you start wondering about this sort of stuff.