Well, I just got finished with the Apple Geniuses - I was actually able to avoid hauling my whole setup to a store by having a specialist remotely access my computer.

The bad news is that when I'd restored the backup I erased everything that they might have been able to save. So my pictures and files are totally gone.

The good news is that it wasn't completely my fault for being ignorant and stuff because my original backup was corrupted somehow and so all the subsequent backups were messed up, too.

The other good news is that they were able to fix my desktop issues at the same time, with no extra charge. And again, I did not have to leave my home, and I can have followup support for 30 days. All for $19.

So... the thing I've learned today is that next time I ought to call Apple Support immediately instead of troubleshooting with DH, since I know nothing and DH only knows PCs well. It sounds like they could have fixed everything if only I had not done a Time Machine Restore. I also know that it doesn't cost an arm and a leg.

Thanks, everyone, for encouraging me to do this. No more what-ifs, and I can use my desktop again.