Hi Domane,
I know nothing about yards (or corrals as they call them here in Nevada), but I know a thing or two about bullies. Ignoring them doesn't work and appeasing them sure as heck doesn't work. Standing up to them does. It is stressful for sure, at least in the short term, but much b etter in the long run. Are there other owners who feel like you? A couple of people filming her behavior would send a strong message.
On the WOE, hey, you can't undo a week's good work. You are still ahead of the game because of that good work! So, just say, "Okay, that's over with. Back to the plan." One thing I have read in several places recently is how sugar/simple carbs are implicated in increasing feelings of depression. It seems to hold true in my life and, also, in my daughter's life. So, although they are not the devil, they may be his handmaidens--at least in large quantities.

Hang in there!