Permits for Garage Conversion?

I have a garage with plumbing (e.g., bathroom, toilet), drywall and tile floors, cabinets (sink). The county called and said they got a report that there were unpermitted alterations to the garage (true). I dont want to loose any of this renovations and I usually sleep there or do business stuff. I also use it to put storage. I do not rent it out. But i did close my garage door with drywall, 2 by 4's..etc.. WHAT CAN I DO? is there a fine? will i take it down? or can I get a permit?