Your instagram video of it now is visible. This isn't minor surface rubbing. You're affecting the integrity of the tire. If I'm interpreting this right, you've worn/cut a channel 1/2"+ into the surface of the tire, splitting the tread. Here is your tire, next to a new BT45. That entire channel that the arrow points to is new on yours, right?
damaged tire:
new BT-45:
Buy a new rear tire (not a 140/80/17), and chalk it up as an investment in your riding education. If you're including shop costs to modify any of the chain links and adjust the chain slack, getting a new tire put on correctly isn't much more.