you should go talk with your doctor about that.
problems with sleep can be caused by some organic dysfunctions, psychical stress, stimulus overload or a unhealthy livestyle.
on a long time period lack of sleep can cause serious physical and psychical damage to you.
stop the valerian stuff, its not evidance based medicine and as you see it doesnt help you.
better smoke some weed around 4-5h before you want to go to bed or do some sports, get your body exhausted.
otherwise you can try benzodiazepines. but you will need a prescription for that.
depending on which problems you have, like falling aspleep try Brotizolam or Triazolam. these ones take hold on for a shorter time, help falling asleep and dont knock you out that hard.
if you can't sleep the night through and wake up often try Nitrazepam, its effect keeps for more hours, but you may have trouble waking up and will be sleepy all day. the dose should be calculated by your doctor as benzos are addicting and wrong doses can lead to accumulations and hangovers.
as for other medicine you can try Zolpidem, Zaleplon, Zopiclon, Indiplon, Ramelteon
these seem to be promising as there are less hangovers and side effect. but that are newer medications with less clinical experience on them.
nontheless all these are drugs which on a long term usage are toxic are addicting and have side effect.
use it for a short period only and only consulting your doctor.
they "cure" the problem with the sleep, but not the problem which causes it!!