After saying hamapil at night can someome think in Torah untill falling asleep? If someone thinks in Torah before saying Hamapil, he might fall asleep without saying it?
Answer:
One may certainly think in learning after falling asleep, and this is recommended practice. Aside from the value of Torah study, it is a sure way to fall asleep quickly!
You are right that thinking in learning while laying down is a recipe for sleep, and it is better to say hamapil first.