Help HTC Desire can only connect to wifi when router very close

[yabbayabba]

I accidentally dropped my phone today, got back tonight and tried to connect to my home wifi but I can only really stay connected while in the same room as the router. If I leave the room the connection drops. This only started today and I'm worried the drop may have damaged the phone's ability to connect to wifi.

My home wifi says 'Not in range, remembered' but other devices can connect fine all around the flat. What could be the problem?

Thanks a lot