Hey Lisa,
I'm not familiar with your routers and card product numbers - BUT, if everything has been running good up until now, and you've re-installed all software (problems from a recent computer crash). Then that would leave only one thing.
The Transmitter in your PCI/USB Wifi card, may have Stopped transmitting at full power. This would explain the poor 'sending'. Can you swap/try a different WiFi card in the PC ?
Garry