HELP! Odometer went from 180K to 64K...

I suppose it'd be worse if it went in the other direction, but I'm afraid I have some serious problems with the computer/electrical system and I'm looking for some help.

The other day, my gauge light burnt (?) out. The indicators for the gauges works, the lights for the odometer works, however, the main dashboard light (for the spedometer, etc.) burnt out.

Then, a couple days later, I started my 2000 Sunfire and the odemeter, which read 185K last time I shut it off, now read 64K.

I need some help and suggestions on what to look for before I have to bite the bullet and take it in.

Any help or suggestions greatly appreciated.

I also have the broken door hinge problem that I have to fix. Argh! My battery has run dry about 5 times because of this.

I should just sell this thing since I can now tell people it only has 64K on it. LOL.