Possibly a simple and / or inexpensive fix?

Truck (2.4 liter) recently began to have trouble accelerating. Replaced fuel filter, and added injector cleaner to new tank of gas. Drove about 20 miles total; ultimately had to park it as it would no longer accelerate in any gear. Shifts easily / clutch pedal springs back as normal. Tranny fluid good. No engine hesitation. O2 sensor / throttle body / injector affordable, but trans is not. Very fixed income.