Upgraded to WP 3.0.4 but theme/plugins didnt work. Tried to revert to 2.9.2

Upgraded to 3.0.4 last nite. Got it up and running fine. But realized my theme and plug-ins were no longer compatible and kept locking me out of my admin panel. Finally deactivated all the plug-ins and the theme worked but I had to even disable akismet which of course isn’t ideal. The theme I use(d) was Mystique.

I realize now this was dumb but I decided that if I could just go back to WP version 2.9.2 that all would be fine again. So I attempted to reupload those files in the same way I upgraded. (First I uploaded/overwrote the entire wp-admin and wp-includes folder. Then I uploaded the contents of the wp-content folder and then the base files.) But I wasn’t able to restore it.

So I then figured that I could just reupload the 3.0.4 files and it would go back to working again and I’d just have to choose a new theme/plug-ins. But that didn’t work either.

I have a database backup I did before the upgrade last nite. What can I do to get my blog back up and running? I’ve clearly altered some files I shouldn’t. Can I get it back? Do I have to wipe it an reinstall? Please help. UGH. Every upgrade presents terrible problems for me. That’s why I try not to do them… Any assistance is appreciated.

I’m completely down. My blog address is https://www.erinjackson.net/blog