No WiFi and Short Battery Life iPhone 3G

About a week ago, I noticed that my Iphones battery life was extremely short, even when I was not using the Iphone. (It goes dead overnight.) I changed some of the settings to minimize battery usage, but that didnt do any good. At about the same time, I realized that my Iphone was not picking up WiFI networks (even if set right in front of my WiFi router), and in fact the settings have No WiFi in grey both in network and on the general settings page. The WiFi address under General, About is N/A. I followed instructions on Iphone help pages, and reset network settings (several times) and that didnt help. I restored it to factory settings (several times) and that didnt help. I have read so many postings on this forum and followed some of the advice, but havent been able to find anything that helps. (I have not tried putting it in the freezer as Im a little nervous about that...) Of course, Im out of warranty, and not near an Apple store... This phone worked perfectly before the last update. I am so frustrated. Please help! Thanks.
Iphone 3G iPhone OS 3.1.2 PC XP