Since you were able to write this report with a shattered shoulder, it appears that in the end you will recover.
However, this is exactly why they have all of those safety warnings on the ladder. One of those warnings is that you are to never use the top step. If you have to hold onto the house for "stability" even if you missed the warnings on the ladder that should have a very big clue that you were not in a safe situation.
You can take a "great deal of care", make sure it is "evenly set", climb as "carefully" as you want, and you can step down "slowly" all you want. But if you use the ladder outside of the warnings there is really only one person to blame.
By the way a 200 pound ladder(Type III) is the lowest rated ladder and is considered "light-duty".