HOM WIFI WORKS BUT NOWHERE ELSE SUDDENLY iPhone

just yesterday my iphone 3gs suddenly stopped working on the network at work. its connected, has full bars, but that spinning wheel just keeps aturnin with no results. i restarted my phone, forgot the network, deleted the 1st dns number, restarted the wifi multiple times, tried connecting to a different wifi (at a restaurant with the same issue) but when i got home the wifi there works... i even reset my phone to factory settings, and downloaded the most recent update... im a hot minute away from smashing the bjesus out of this phone.
pllllease help!
Mac Pro Mac OS X (10.5.7)