Ahh ok the quickest way to fix that is:
1. Create the upload folder again, move all the files back into it, then go into admincp and into the settings to reset the Contact US / URL settings and save the new forum url w/o the /upload on the end.
2. Now move the files back into the root and it's fixed.
If you still have issues after that, upload the tools.php from the "do_not_upload" folder into your admincp folder and fix the cookies in both areas.
Should be ready to rock and roll

.