You may be a character in a story if…
…the events in your life are too tidy and symbolically relevant and foreshadowing follows you as lengthily as your shadow does by the light of the setting sun.
…you are hardly ever left alone, or, when you aren’t, there are usually more than two or three others.
…all your closest friends talk suavely and succinctly, always to the point, in fact, to multiple points since they speak with multiple layers of meaning. …the only people to speak in particularly original dialect/accent/diction are the ‘walk-ons’ of your life, though you can’t be sure since they only ever deliver one, maybe two, lines before leaving your life again.
…your thoughts have a voice but also a meta-voice and, although you can sometimes manage the primary voice, that meta-voice leans closer to a “voice in your head” demanding psychiatric help.
…overly sympathetic weather or if the items/colouring/lighting of the room around you change depending on your mood, what just happened (and that unsettling feeling of what is about to happen), and who else is in the room with you. In potentially bad fiction, you may notice a re-arrangement of the room since you last entered it.
…and how to discover your fate
Not all characters are created equal and, for the sake of remaining positive, we’ll assume that since your attention span has lasted this long that you aren’t too minor a character in this story.
Philosophically aside, we won’t assume necessarily a life after page for you. If you care to believe in one, that most likely reflects consistently with your religious/spiritual disposition, or, should page end be nearing soon, for instance, if the climax is already resolving, with your tendency to clutch at last second redemption.
This next bit may be crucial to your survival:
Is your ‘character’ changing as the story proceeds?
If yes, I’m afraid the chances are high that this is a stand-alone story that will end. Your best chances are to fight change in yourself as much as possible. I realize that if you have falsely concluded being a character in a story then this is horrible life advice. Take it with full responsibility. Should your outward changes be against your inner sense of self, be aware that your creator may be forcing your movements. As displayed in last summer’s movie, Ruby Sparks, beware the tug ‘o war on the strings with your malevolent puppet master or you may suffer mental dissolution or, worse, total rewrite.
If no, there are two possibilities. First, you may not be the protagonist in this story but, since you’re not merely a minor character (see above), there is still hope. I suggest behaving intriguingly mysterious enough to seduce and coerce your creator into total re-examination of the story retold from your perspective (eg., Midnight Sun). Do note that this will not really prolong your life but rather loop it to relive the latest crisis in duplicate. Sorry about that.
Second, however, if you are the protagonist and yet manage never to change despite the crises and challenges around you: barring poor fiction aside, you are the prime character of serial fiction! Congratulations! As long as your audience loves your obduracy and cinematics you can look forward to many future crises, albeit, formulaically repeating your most recent. Enjoy!