Hi Ike,
Unfortunately I can't help you, but can at least give you moral support, as the same thing is happening with me! Last week I did have a nasty virus called Bravesentry and I've been through the mill with that, but I think I've managed to get rid of it now. I've done all the things I was told to do by the experts and have scanned the computer since then a million times. I've even wondered if maybe it was the scanning logs that are causing the rapid shrinkage, but it seems very unlikely indeed and like you, I'm very worried I'll run out of space. I could really do without all this grief.
Come on all you geniuses out there, help us out!
Kind regards,
Ian