I feel like this is kind of a weird question for me, and maybe some others might feel that way too...like it kind of assumes that my 'identity as an artist/writer' is more of a means to an end than an intrinsic part of my lifestyle. ^^;
Not that there's anything wrong with that-- for many people, writing stories and/or drawing comics is just a hobby that makes them happy, that they might easily move on from someday. And that's natural and okay...but it's not everyone.
I think the day I don't have any more stories I want to tell is the day I no longer want to exist on this earth. Like, even if I don't want to take the time to polish them up or even write them down, I think I'll always be making up little scenarios and characters and thinking 'oh, wouldn't it be cool if x, y, and z". It's just something I do; something I've always done.
Asking if I might someday be 'finished' or if I might have to force myself to continue because I'm 'attached' to it...it's like asking if I'm 'attached' to consuming food. I guess technically yes, but you're phrasing it as if there's a sensible alternative...?? ^^;;;
I guess to actually try to answer the question (basically, what I would do if I wasn't a storyteller) there are other hobbies I have that I'd probably default to-- composing music, for one. But I also think I'd do more critique. Film, literature, theater, video games; you name it, I'd analyze it. ^^
Basically, my brain has two modes: if it's not creating/putting things together, it's taking them apart and trying to figure out how they work. The main reason I don't do a lot of critique now, even though I enjoy it, is because I'd rather focus on my own stories...without them, I'd have all the time in the world~