>>> but when I plugged in my xbox ethernet cable,
>>> it kept trying to aquire the network address,
>>> and obviously failed
Which network adapter is trying to acquire its network address - the one in the PC or the Xbox?
If you've enabled Internet Connection Sharing on the PC's Wireless Network Connection, then Windows should have configured your Local Area Connection (the "wired" network adapter) with the IP address 192.168.0.1 and Subnet Mask 255.255.255.0
The Xbox should get its IP address automatically by DHCP from the PC. If this isn't happening, try disabling Internet Connection Sharing on the Wireless Network Connection, reboot the PC and then enable it again.