Something major is wrong with my blog and now I’m scared

Ever since I’ve upgraded to 2.1 from 1.5.2 I’ve had nothing but problems:

– white screen when publishing due to autosave
– missing archives at the ‘more’ statement
– my wp-admin/plugins.php page is blank
– (see my profile for more unanswered problems)

and now this: My comments do not post where they should be posting.

For instance:

Here is a comment I received last night:
http://www.petlvr.com/blog/2006/04/why-it-is-essential-to-crate-train-your-pit-bull-terrier-puppy-dog/#comment-47984

It was really posted on this entry:
http://www.petlvr.com/blog/2007/04/official-slowdown-notice-hart-empire-network/

The comment appears in the dashboard Comments section under the first link above, but shows up on neither post (and I have not deleted anything).

The comment even shows up in my sidebar of Recent Comments.

the URL is http://PetLvr.com/blog/ and there is over 2400 posts in there. Every day I am finding problems with my archives.

I can’t even upload a plugin to show you all the plugins activated, because I can’t see any plugins to activate or deactivate it.

This is a total mess. Can we brainstorm here? What are my options to FIX these major wordpress problems? I’m on a slowdown this week, so not posting much might make things less complicated. I think the biggest mistake was that after I upgraded from 1.5.2 to 2.1 version, everything LOOKED and WORKED okay – without me 100% testing it.. but, after testing it and posting for 3 months later .. it just compounds the error.

Take care.
HART