How to stop erroneous Paste

I made a mistake and am trying to figure out what to do about it. I created a new sheet and was trying to simply paste a couple cells from another sheet into it. Unfortunately, I made the mistake of having an entire row selected when I did the Ctrl-V, so now Excel is repeating the paste out into the boonies. Esc does not stop it. I guess I will wait until it hits the stops, somehow. Out of memory, cell range limit, or something? Is there any other way to try and stop this? I had a lot of unsaved work put into this workbook before this happened.