300 mg is best taken when on a empty stomach to maximize its effects (although 300mg works well for me even when eaten although i nowadays never take more then 150mg)
The not walking straight thing is one of the effects lyrica has on people but there should be at least some kind of body buzz / happy feeling along with it.
take into account that it can take up to 4-5 hours to feel effects when there is food in the stomach/system.
So prob the drugs kicked in while you where sleeping.
for me most of the time i get a motivational / energetic feeling with a weak body buzz.
its def a weird drug with a lot of potential outcomes on the effects (sedate, hungry,energize,happy thoughts ,groggy,frustration etc etc
some days the drug seems to barley work other times i am sky high
Its def. not for everyone.
I found that redosing the same day doesn't do much to anything .
So far the few friends of mine that tried lyrica all got a nice buzz from 150 mg there first time and experienced it as very pleasant.
i would say if 450-600mg doesn't give pleasant effect its not for you i wouldn't experiment with much higher.