96 Geo Tracker transmission issue

I have a 96 Geo Tracker, 4 door with a 03 72le 4 speed automatic transmission. My problem is severe lack of acceleration power. The engine runs good and revs just fine in park or neutral. When driving it just doesn’t want to accelerate especially going up hills. The transmission will shift, but it hits really high rpms when it does. When it hits fourth gear it only stays in briefly and shifts back to third. It won’t do anything in fourth. Am I looking at a torque converter issue?