That's a high gravity beer (projected OG of 1.088) and you should have used a yeast starter.
What was your measured OG?
Those liquid yeast vials do not nearly contain enough active cells to kick off healthy fermentation, with few exceptions noted.
I wish they put a warning on those vials: May need starter! It looks like everyone has to make that same unintended mistake at least once, I did. The LHBS where I obtained all the ingredients from, did not even mention the word starter or even try to sell me 2 vials, as in "you'll need those."
Anyway, my advice is: do not pitch a single vial. Unless one has money to burn and pitch 2 or 3 vials, it is fairly easy to make a good size starter, even without a stir plate.
Some may call it a nuisance to make starters, I'd call it "foreplay to brew day." You may quote me on that.
Where to go from here?
I'd say leave it alone and take a hydrometer test after a week from now. Report the reading back, if you want.
...I opened the bucket to see about 2-3 inches of bubbled head...
Isn't that a sign fermentation was taking place. You should have left it alone and let it do its thing.
There maybe some off flavors from the second drill-stirring, maybe not. I hope that drill didn't drop any extra bugs into your wort. Those drills are hardly sanitary. Even hovering and breathing over an open bucket of wort could cause infections. You got to ride this one out and see where it leads.