I wouldn't drive or anything like that, but in general the Gabapentinoids are pretty safe, even if you take exponentially higher than prescribed dosages. Some people experience side effects similar to drunkenness when taking such high doses so, just like actually being drunk, you open yourself up to the potential for injury i.e. falling or something. If you feel okay don't stress out and lay down if you feel you can't remain upright anymore. You'll sleep well and probably wake up feeling just fine.
For reference, 600mg is the maximum recommended dose for Pregabalin (Lyrica) per day so you definitely are not doing anything crazy.