I did the same thing when I was new to my wing, the secret is to keep you eyes up and straight forward until AFTER the bike has come to a full and complete stop, never look to the side, or down, at the last second or the bike will immediately tip that way. On a smaller bike it is no big deal to hold it up after it starts to tip, but not so with a bike as big as a wing.
When stopping especially on a corner or turning in a parking lot ect. you must always first straighten the bike and pick a focus point ahead of you before applying the brakes.
With practice you will become more stable on the wing than any other bike you have ridden, but it is more unforgiving of poor skills at low speeds.
Now after 7 years of practice I can ride my bike at less than 1 mile per hour, come to a full 1-2 second stop without using my feet, and can turn her on a dime, and stop in the bikes length at speeds up to 25 mph, but still I need to keep practicing as I know folks who are much much more skilled that I am.
PS. Yes I do still drop my bike on occasion, always in parking lot practice though as that is where I am pushing my limits, don't worry about it though as that is exactly what the engine and saddle box guards are for.
Once the bike starts to go beyond a few degrees just let her go, don't get caught beneath her, besides it's just practice on how to correctly pick up a bike right?