Ok, now that you got it fixed, to back fill the trench.
1) Fill the bucket with spoils.
2) Lower the bucket so it's just off the ground
3) Lower the box blade so it is just off the ground (and it HAS to be dead level). Set the 3pt lift lower limit to that point.
4) back into the spoils line so you are pushing 1/3 to 1/2 of the box blade's width.
5) raise the box up, go forward and repeat step 3&4 about 15,000 bazillion times untill done.
As you know (now), you had the loader up way way way too high. There is no need to have it any higher than about 1 foot above the ground when the tractor is moving. Also, your technique looks like you were filling the bucket then backing up, turning and going forward to dump? You should be on the far side of the spoils pile, filling the bucket and going straight forward to dump, steering around the spoils. Then backing straight back to repeat the process.
Anyhoo, you didn't get hurt, the tractor didn't get hurt and you have a sense of humor about the whole deal. Thanks for sharing the scary moment with us!
jb