Same thing happened on my '97. I had to roll down the window and use the exterior handle to get out of the truck for a couple trips. The problem is (obviously) not the latch.
There is a metal rod that extends from the interior door handle to the latch mechanism inside the door, near the rear edge of the door. Where that rod connects to the latch mechanism, there is a little plastic connector that keeps the "L" shaped end of the rod and the latch connected.
On mine, the rod had popped out of the plastic connector. I re-inserted it, and that was that.
It's possible that yours may have broken, but like I said, it's just a small plastic peice. I doubt it would cost more than a couple $ for a replacement.
Take the door panel off, pull back the plastic sheet, and have a look. You'll see what I'm talking about.