Over-carbed?

I opened my first batch of beer yesterday, a nut brown ale that was in the primary 1 week, secondary for 2, and in the bottle for 8 days. I was curious to see how it was doing, so i put one in the fridge for roughly 5 hours, and after opening it was carbed already . It tastes good and there was a decent head on it, but the problem is it's really fizzy, almost like drinking a coke, and seems to have too much co2 or something. It doesn't foam over like i have been reading when beers are over-carbed, but something just isn't right. I have a feeling the answer will be to wait another week or 2 and try it again, but i was just wondering if anyone had any experience with this? I hit my FG right on, and actually thought that i didn't add enough priming sugar (corn) when i bottled, so i am not sure if this is normal.

Refrigerating for only 5 hours is the problem. It didn't allow enough time for the co2 in the headspace to dissolve into the beer. What happens while the beer is carbing after priming is the co2 is produced. Until there is lots of it, or the bottle is chilled, it tends to not be easily dissolved into the liquid. Once it's chilled, though, it readily dissolves into the beer. As you know, 8 days is early to open it, so it's probably not fully carbed. But for the next one, chill it at least 24 hours, and I think you'll notice a big difference.

I keep bottles chilled for 48 hours before I open them to ensure the CO2 has fully dissovled into solution after its cooled down.