my truck keeps stalling out at low RPMs, what's going on?

What is your question?

I have a 1992 Toyota Pickup with a 22RE. I started having issues similar to what a dead battery would do so I started there. The truck kept driving while driving or it wouldn't turn over (radio starts going out, flickering of lights, etc.) so I got a new one and after a new battery the truck kept dying so I got a new alternator, cleaned the terminals, re grounded and did all the basics I know how to do on my own. I can't figure out what else could be wrong but now the problem has shifted from dying and not starting to just dying but (most of the time) being able to start again. At stop signs or lights when slowing down past 1500 RPM, the truck just dies. And ideas as to what can be happening? my next guess is a fuel problem? Anything helps, thank you!

What makes this problem better or worse?

higher RPMs make is better

How long has your 1992 Toyota Pickup had this problem?

few weeks