Forgive me if this has been covered before, I searched to no avail.

2001 f150 5.4 4wd electric switch to select 2wd 4wd 4wd low

Parked at the river in 4wd low for an hour or so.
Pulled the trailer about 20 feet in 4wd low.
Shifted to 2wd
Drove about a mile on dirt road at 3 or 4 mph.
Noticed whine of low gear, tried to shift to 4wd, 2wd, low, 2wd.
Tried reversing a few feet.
Foot on brake in neutral
Foot on brake in park.
Barely rolling in neutral .
Don't think it's in 4wd, turns ok, but soundl like its in low, and mph reads about tripple...
Any suggestions?
Or is this going to be hundreds and hundreds ant the tranny shop?

 

Explain the speedometer reading triple.. when you are rolling forward are the tires trying to bark at you?