so how do i get the airplane to be loaded when you call GSX, as its connected to simbrief so i have the passanger count on there
If you have a Simbrief plan activated for the current airport ( GSX reading OK in green ), the passenger number will be taken from that, so the airplane payload is irrelevant in that case.
As I've said, if you see the pilots/crew boarding, and the jetway hasn't disconnected in the meantime, there's no reason passengers won't show unless, for any reason ( Simbrier of Payload ) their number would be set to 0.
You don't say which airplane you use. Another possible reason why the passenger number is 0, is the airplane has some kind of integration with GSX, so IT has set the passenger number to 0, because it needs to control it with its own logic, so you need to follow its logic, if this is the case.