It could be a few things,
remove the cooler, make sure the paste is only on the die.
if it's all over the place, clean it with 99% ISO, dont worry about things appearing wet get all that excess paste off of everywhere
My best experience has been to add paste and brush it on thin with an actual razor, do it as thin as you can
unlike a cpu with the heat spreader, you are making direct contact with the die.... less is more
again you don't want it spilling off of the sides.
Then when you put the cooler back on, make sure it sits firm, but don't crank it down tight. ( feel this is your problem)
I doubt very much you've done any damage.