Hey man, don't get too down. Everyone has to learn how to successfully grow. Recreating nature isn't easy; you should be happy that you got it through so many weeks of flowering. It took me 3 tries before I was able to actually harvest anything, lol! All it means is that you try it again.

If the entire cola isn't covered with mold, I would see if you can surgically remove it (but only if you think you can get it ALL). Then dry and cure it like normal (constantly check for mold). I doubt it's a total loss; maybe make some cannabutter with it or something, using half the amount of butter.

Hakuna Matata, friend!