Since you replaced the LCD yourself that required you to pretty much do a complete tear-down your phone to get to the display assembly. Hopefully there was no physical damage to the logic board in that initial accident (I.e. the WiFi radio chip wasn't damaged). That would involve the need to replace a the entire logic board as the chip is soldered in place. But to open up the phone, that would probably require you to disconnect the antenna from the logic board, so perhaps all you need to do is reconnect it, or at least just re-seat its connector. This sounds likely considering the proximity matter you referred to.
Other than that, have you tried just restarting your router? I know you mentioned connectivity not being a problem with others but basic home networking isn't that simplistic, Depending on how extensive you or someone has configured you router's settings, you need to focus on your phone's WiFi connectivity, not everyone else's. Another way to check things is to try using a work or neighbor's WiFi network to see if the problem is just with your home network or just your phone.