iPhone 4 won't connect to home wifi

The following has troubleshooting information that may help: iOS: Troubleshooting Wi-Fi networks and connections

Hi Guys!

I am having the exact same trouble and have already tried all the fixes on the Apple support page recommended above, including:

Unable to connect to a Wi-Fi network

1. Verify that you're attempting to connect to your desired Wi-Fi network.
2. Make sure you're entering your Wi-Fi password correctly. Passwords may be case sensitive and may contain numbers or special characters.
3. Reset network settings by tapping Settings > General > Reset > Reset Network Settings. Note: This will reset all network settings including:
   • previously connected Wi-Fi networks and passwords
   • recently used Bluetooth accessories
   • VPN and APN settings

I don't have any other issues with my phone and it stopped overnight...I hadn't changed any settings. I've hard restarted it twice, done the most recent update, turned Bluetooth off and on and still no connection. The phone sees the wifi networks, it just won't connect and even my 3G is super weak.

I'm leaving on a three month trip in 5 days so ANY helpful advice would be appreciated!! I'm taking it in to an Apple Store tomorrow.

Thanks!!