short answer:
depends on how you store your email. If it is stored on the mail server, very easy fix:
(in either ALWAYS make a copy of any local .pst prior to beginning ANY repair process)
Sounds like you only borked your local cache: to rebuild simply delete the local account, close and re-open outlook, then setup a new account. Email from the exchange server will auto-download and rebuild your local OST.
If mail is stored ONLY in a local .pst -> you can "hope" the profile is messed up, and your local .pst is recoverable. make copy of existing .pst, delete account / profile (w/ Outlook closed, go to control panel -> mail applet). re-open outlook follow steps above / wizard within outlook to setup a new account. Next File, open browse to original file, open it (cross all fingers, toes, etc.) and you should your original mail show up within a Personal Folder on the left side panel of Outlook.