"Unable to connect" to home network

I recently updated my iPhone 4 to iO6 I believe. But ever since I did that, my wi-fi either won't connnect or is very slow. My internet works find on 2 laptops but no longer on the phone. Ideas?

I have tried:

Turning the phone off an on.

Forgetting the network and re-entering info.

Resetting network setting. Turning phone off and on after.

Logging into my router to change the DCHP lease time, worked before the update but now doesn't (also when I try to log into the router, it's incredibly slow - tho my internet works fine - so if anyone has ideas on that too, because that seems odd)

I'm out of ideas.