If you poured you beer back in the fermentor, you more than likely oxydized your beer..
Next time, maybe you want to solicit help or ideas from here, BEFORE you do something that more than likely is going to be worse than had you left it alone.
You misjudged the sweeteness. More than likely had you let the beer carb and condition, it would have been prfectly fine...you really can't just what a beer is supposed to taste like until it's actually done.
There's nothign wrong with bottling a beer at 1.019, or any gravity, if the beer was actually done. If a beer is finished fermenting, meaning all the unfermentable sugars have gone, then that's it, the beer is finished. Nothing will happen if you add more yeast, the beer is done.
Your beer was more than likely perfectly fine, despite your panic/knee jerk reaction, but now it might not be......Next time be less hasty to do something so drastic.