IPhone 4s lagging after updating to iOS6?

I recently updated my iPhone 4s to iOS6 and it has been lagging ever since. I had no problem with my phone before I updated it. But now the battery is draining very fast and the internet and basically the phone itself it lagging so much. I barely have any apps and it's certainly not a problem with that. Also it's repeating notifications. When someone texts me, my phone notifies me and about a minute after, it notifies me again.

Is anyone having the same problem or does anyone know how to fix it? I tried rebooting it last night but it didn't help solve the problem. I got the phone late in August so it's pretty new, if that helps… Thank in advance!

The only thing that is the same for me, the the repeat thing. It happened to me before the update though.

For your notification thing happening twice, check on settings, then to notifications, click iMessage and on there you should see that it may have defaulted the notification to "repeat notification twice" or something like that