Connect your computer to the router with a cable and turn off your airport card. If things don't speed up then it is not your wireless. Next, connect to DSL modem directly, if things speed up it is your network. If they don't, then it is likely your DSL. If it is your network there are lots of things that can be done. If it is your DSL then all you can do is call verizon and complain.
Please post with the results if it turns out to likely be your network.