I DID IT! OMG my head is like mush right now but I did it.
OK Here's what I had to do:
Fresh install of Mybb 1.8*
export the OLD UPGRADED database in two stages: EVERYTHING EXCEPT the theme tables
ONLY the attachments and attachtypes (whateveritscalled) tables.
IMPORT the the database minus themes.
Check things. ACP > Tools > rebuild caches and recount and rebuild
UPLOAD via FTP my OLD uploads folder and its contents
IMPORT again the attachments only tables
Check things. ACP > Tools > rebuild & recount attachment thumbs.
Check threads with images. VIOLA! images seem to be there. awesome
NOW I installed automedia. NO PROBLEM and I left the stupid table prefixes the way they were in the forms. Must have been a glitch.
NOW I can install the custom theme I made for 1.8*
so, although this was quite the problematic upgrade I'm glad it happened because I have other boards to upgrade and I really can't have those messed up too!
Thank you for your help expat! It really was helpful because you got me thinking creatively!