Errrr... I suspect the trouble sleeping is due to tje other stuff in your pre-workout; not the creatine.
Creatine is not sometjing to be taken in single doses a few times a week... it can, but the effects and benefits of it won't be realised this way.
Dosing protocols normally suggest load-maintenence cycling or circa 5g/day continuously to build up creatine to much higher concentrations in skeletal than normal, which does a number of things:
1) Creatine acts as a phosphate donor to ADP, the byproduct of muscle contractions, meaning the contraction can last longer and harder.
2) If consumed together with carbs, thosr carbs bind to creatine. This means more intra-muscular glycogen for the muscles to use once the creatine itself has been used up. The fun result of this is, as water binds to glycogen, muscles that appear bigger and harder.
3) High levels of creatine down-regulate the effect of myostatin, meaning that the breakdown of muscle that occurs during and after exercise is reduced. This means your body spends more time growing = bigger muscles.
Now it does all of this over a period of weeks and months: it has no instant effect other than to suck up water into muscles. Greater power output and mass come in between 6-10 weeks after dosing daily.