iOS6 iPhone 4s wifi problems please help!

i updated my iphone 4S to iOS6.1.2 and the wifi started to get some serious problems, at first it was greyed out, then afew reboots it wasnt grey anymore, however when i turned it on there wasnt ANY wifi access point (i was 1m away from my router and my pc and ipad was working fine). i started turning wifi on and off and finally i can see my router, however as i typed in my passcode it just pops "unable to join" any suggestions??