Can you hear the fuel pump when you first turn on the ignition prior to cranking the engine? it should run for a few seconds to prime the engine.
It makes a quite distinct sound if you listen in a quiet garage.
If not it could be a failed pump or check the relevant fuse. Assuming the swapped relay was ok. It usually is the relay. It's a common problem.
If you can hear it, start looking elsewhere.
Can't hear anything. Looks like the fuel pump, I guess its a complete in tank unit?
Thanks
Gordon