I had the groggies for about the first month as well... kinda felt like I was in a fog... I tried a 0 NIC juice about halfway into my first month to see if it was over-nic'ing.
Nope, still had the groggies.
Drank tons of water and juice (the real kind, not the one with nicotine in it

), so despite my coffee addiction, I never really got dehydrated.
The only thing I can attribute the "spaciness and the groggies" to would be detox of the 9,453,867,729,900,000 other chemicals that we used to take into our systems via the stinkies. It eased off for me right at about the 30 day mark, but who knows? Each person's metabolism is different and will purge the crud out at a different rate as well. Some things posted that will help are to definitely drink plenty of fluids. (Gatorade isn't bad, but you'd be better served by juices and water, helps to detox you faster), and to also, like Crxess said, take cleansing breaths. More o2 to the brain is never a bad thing!
Hope that helps, and stick with it, it DOES get better and easier!