'95 F-150 Fuel System issues
 

I recently bought a 95 F-150, A/T, 5.0, Dual tanks shortbed.
Ran great for the 1st hundred miles or so, then while going up a mild slope, started running rough (underpowered) & CEL came on. A mile or so later, it just died. After sitting about an hour, I was able to make it home, but barely.
I checked everything I could think of and things looked fine. It was running great & then it started running crappy again. I noticed the front fuel pump sounded a bit louder than usual, so I attached a pressure tester & it was only pumping 18 psi., compared to the 32 psi. reading I'd gotten earlier.
Does this sound like a weak pump issue? I'd hate to waste the time & $ on replacing something unnecessary.
This is an ongoing problem, so any advice would be greatly appreciated.