I've always been told by my brother that "blue light" triggers sleeplessness. Siguro if you plan to sleep earlier, avoid contact with things that emit blue light (ex: computer, tablet/cp, etc.)
avoid stress and anything that may trigger your brain to be active.
try playing relaxing music, preferably instrumentals, sabi ng karamihan sa kakilala ko nakakapagparelax yung mga piano instrumentals. turn off your lights. try a relaxing warm bath before you sleep or drink a glass of warm milk.
avoid caffeinated drinks (including coke). also, try to empty your mind before bed time.
should it proves ineffective, seek professional help. well, it does not mean that you are mentally ill. probably, all that built-up stress caught up to you and your body just needs a little aid from those who are more capable than us - the normal people.