Connectivity

I think you mean that you configured your router at 198.168.254.254

in that case i would go to your network properties of windows.
set a fixed ip of 198.168.254.x (x= anything between 1 and 253)
set your gateway fixed at 198.168.254.254.

then open the explorer and type the adress of your router. Now you should be able to change the ip of your router and if needed enable DHCP.

if you enable dhcp go to your computer and set it do dynamic adress or get adress from dhcp.

or

set your ip settings of your computer as of it was before.

good luck.