It depends how you fell about death itself ! If you fear it, it will cause you to panic and to remain as a ghost stuck on the spectral realm, hunting dreamers when they dream!
A ghost is a soul panicking and lost that need a guide! If that soul isn't guided, it will become fiendish and envy every living entities. Some soul absorb so much negativity they actually end up living of that and will feed of pain and suffering! (leeches Demons)
Dieing brutally feels like a enormous jolt of burning electricity going from your feet to your head.(no pain).
Dieing slowly is the worst, Because you have to let go, if you hang on too much you might, just might stay stuck in the spectral realm with no one to help you.
Ec. 9:5-10; "For the living know that they will die, but the dead know nothing; they have no further reward, and even the memory of them is forgotten. Their love, their hate and their jealousy have long since vanished; never again will they have a part in anything that happens under the sun. Go eat your food with gladness, and drink your wine with a joyful heart, for it is now that God favors what you do. Always be clothed in white, and always anoint your head with oil. Enjoy life with your wife, whom you love, all the days of this meaningless life that God has given you under the sun- all your meaningless days. For this is your lot in life and in your toilsome labor under the sun. Whatever your hand finds to do, do it with all your might, for in the grave, the place in which you are going, there is neither working nor planning nor knowledge nor wisdom."
I'm more concerned about why you are asking the question. If you are experiencing excessive anxiety about this topic, or you are having suicidal thoughts, please seek help - a medical doctor, counselor, or pastor.
Well nobody knows but if you want to know a SCIENTIFICALLY correct answer (don't look if you believe in heaven!) is that the theory of a "Bright Light" is just the chemicals ofyour brain shutting down and after that well....you won't remember cause your DEAD and that's that. There can't really be a heaven or hell cause you have to use your brain to even think of that when your dead and your brain doesn't work any more! So it's just the black. But don't worry or be afraid cause you won't remember cause your memory is in your brain and....you know what I'm gonna say....IT DOESN'T WORK ANYMORE! So yep....nobody really knows but you don't have to believe me. I just like to believe in heaven cause even if it isn't real at least it's hope and something to hold on to.