I would HIGHLY recommend that you leave it covered till you have lots of time and $5,000 ready to dedicate to the pool rehab.

The fact that it's still mostly full suggests that it may well be practical to re-hab rather than fill in. But the rest of it sounds like you've got a LOT of serious work ahead of you.

More than that, if you want help, you need to post pictures. You can do so using Flickr, Picasa, Google Drive, Webshots and simply linking to the photo.

Good luck!