Kind of looks like the shop was right and hubby was wrong.
The problem you have is that with a bone dry transmission, and running a trans low on fluid repeatedly due to fluid loss, is closing the barn door after the horses done stampeded.
You have suffered some transmission damage and would need a new radiator also; unless you added an aftermarket cooler and bypassed the radiator completely. (Always a preference.)
The same thing as running an engine out of oil. Refilling it may help, depending, but the damage is done and the life expectancy is dramatically shortened; if there is any life left.
It’s time for a trans cooler and new transmission or time for another vehicle IMHO.