Yep, you messed it up. Better put it up for sale on ebay or craigslist and buy a new one...
I'm not sure the reason why MB instructs you put the wood chips in during the last 45 minutes. Only thing I can think of perhaps the smoke emits solids that get in the way of the machine oils and stuff burning up since those solids are deposited in the interior of the smoker. I bet you could thoroughly wipe down the inside--walls, ceiling, floor, heating element housing, wood chip holder--with damp paper towels, let dry, and repeat the seasoning process. You probably don't even have to do that and you should be fine.
Since I use the
AMNPS, I light and then insert it after the smoker temp is around 215°. I like to get the inside smoky before I add the meat or cheeses. I lose some with the open door but the heat and smoke rebuild quickly.