Transmission issue x2

06 silverado 4.3L 1500 2wd
Thought car was in drive but instead was in nuetral. Went to accelerate hard and put it into drive. So basically a slam hard shift into drive.
Drove down the street and truck would not shift out of first gear.
Checked transmission fluid in tranny pan, there are no metal shavings.
Any explanations?
Could it possibly be the shifting module ?

You have to check the linkage; it sounds like that’s defective or out of adjustment.

A good independent transmission shop can tell you that very quickly.

It sounds like you accidentally did a drag strip start. Good idea where to start above, but I expect it damaged something inside the transmission and you’ll need to visit a transmission specialist to get it working again. It’s possible — cross your fingers – whatever the problem is, it won’t be a major expense to repair.

I’ll add that recently I was doing a diagnostic experiment on my Ford 302/C4 truck and I disconnected the transmission vacuum modulator. The effect was the transmission would shift from N to D or N to R, could go forward or backward ok, but when in D it wouldn’t shift out of first irrespective of vehicle speed. Reconnecting the vacuum sources to the modulator solved that issue entirely. So if your transmission uses a vacuum modulator (which I doubt, but if so) … perhaps that’s the problem.

Does your speedometer seem to be working?