i tryed all of this an my iphone wont connect to wifi unless im like 5ft from router

Try Settings > General > Reset > Reset network settings.

Same thing started on 1/30/13 for me first thing in the AM with my iPad mini. If I am more than 10 ft away (line of sight) from my AirPort Extreme I get the not able to join network message even though it is showing 3 bars. I was running 6.0.1 at the time and have just updated to 6.1 with no improvement.

Apple Support determined mine needs to be replaced.