Help! No power!

You wired an electric fuel pump to the fuel sender wire?? The fuel sender works off of a 5v lead from the instrument cluster, nowhere near what the fuel pump requires to operate. You run the risk of frying your IVR (instrument voltage regulator) and possibly gauges. DON'T attempt to operate it like this!
Disconnect that pump and try to get power back to the rest of the systems, sounds like a fusible link may have let go. You're gonna have to get friendly with your VOM and start tracing circuits and checking fuses. Get the Factory Service manual for your car or one close to it in year or model (Dart/Barracuda, etc.); they're available for free over at mymopar.com and contain the complete wiring diagrams for your car.
When it comes time to wire the pump back up, connect your wire to a switched hot lead and connect it to a relay fed off of a fused hot lead to the battery, then connect the relay to the pump.