My initial reaction, although I now see that I failed to type it out, when I saw your post on the New Members thread, was to suggest saving and reloading the game but obviously you have already tried that by now.
If you have NRaas MasterController in play, perhaps an MC Reset Everything run from the Town menu on City Hall/in game computer might help break the cycle?
If not, can you maybe re-enable fall and winter temporarily, make it be fall, and then try stopping the loop?
If all else fails, do you have a save you can revert to from before you engaged the testingcheats tree command?
