Intermittent stalling, Low Fuel Pressure?

What is your question?

I've been having this issue for a few months now, has gotten progressively worse. Vehicle stalls often while at low rpms, but can be driven fine if I keep rpms high. Happens more often while driving in the city, not at all while driving long distances in 4th gear at 50-60mph. When it stalls engine still runs but I get no acceleration from gas pedal. Lights and radio also cut off. Downshifting to get rpms really high usually fixes this, otherwise it will usually start back up after a few minutes, sometimes it will not. I replaced battery terminals, checked cable connections and have tested alternator, all are fine. I've also replaced the fuel filter which was pretty rough, was hard to get air through it. Is this the fuel pump, sensor, or maybe the fuel line is clogged from the fuel filter getting so bad? I am on limited funds and this is my only vehicle, I'd like to be as sure as possible what the issue is before I have any work done, especially if it is an easy fix I could do.

What makes this problem better or worse?

Worse at low rpms, better at high rpms

How long has your 1994 GMC Sonoma had this problem?

3 months, progressively worse