Next time, IF there is a next time.
Bag your fish, only need enuf water to cover the fish by an inch or two.
But trap a lot of air into the bag.
Points for this is that there is a lot of O for them,(keep the numbers down),
and there is little, if any "sloshing" to traumatize the fish.
The trip could have been don in 1/4 of the time,and being in bags,
are easily floated then acclimatised to their new home.
You will go thru life as a large learning curve.
I'm afraid you just went thru one.
Pity about the losses tho.
Alan 104