Q: Truck is slow and sluggish to start and will only run a few minutes before shutting off and hisses when it does

I recently had to replace the serpentine belt because it jumped off. I didn't drive the truck more than a minute or two before i realized it. After replacing the belt now the truck is slow and sluggish to start and cuts off after a few mins while idling or when driving(giving it gas). When it shuts off a loud hissing sound like air escaping comes from the back of the engine. It was fine age considered before replacing the belt. I know it isn't the alternator because it cuts off when hooked to another car using jumper cables. I've been told by shade tree mechanics it is the fuel pump. I unfortunately have no knowledge of vehicle mechanics. Any help would be greatly appreciated.
My car has an automatic transmission.