What you said makes no sense, please explain.
If you're on a regular ISP (no exchange server), you should simply have a "Personal Folders" account/profile and possibly an "Archive Folders" also open. Each has an Inbox. You can create multiple "profiles" in Outlook, but when Outlook is opened, the default folder for that particular "profile" is opened and displayed as the "Personal Folders". You can then do a File/Open to open other profile PST files from other profiles and they may all be called "Personal Folders", but where the data is stored is in a different PST file.
Now, you said you have "one email account/profile as a separate ACCOUNT IN THE INBOX". Are you saying that you created folders inside of the main INBOX which replicates the regular folder structure (has another inbox, outbox, sent items, deleted items, etc...) all stored inside of ONE inbox? Is this what you're saying that you have?
+Personal Folders
-+Deleted Items
-+Drafts
-+Inbox
--+Personal Folders(2)
---+Deleted Items
---+Drafts
---+Inbox
---+Junk E-mail
---+Outbox
---+Sent Items
---+Search Folers
-+Junk E-mail
-+Outbox
-+Sent Items
-+Search Folders
If so, when you delete an item from the inner most folders, it goes to the outter "Deleted Items". If you send an email from anywhere, it goes to the outter "Sent Items". To keep things separate, you need to try and recreate two separate outter folder structures. Try dragging the inner "Personal Folders" to the very bottom of the list and see if it will create a separate folder structure for you. You may have to go into options to tell it where (which PST) to store inbound and outbound mail.
What you should end up with would look something like this:
+Personal Folders
-+Deleted Items
-+Drafts
-+Inbox
-+Junk E-mail
-+Outbox
-+Sent Items
-+Search Folders
+Personal Folders(2)
-+Deleted Items
-+Drafts
-+Inbox
-+Junk E-mail
-+Outbox
-+Sent Items
-+Search Folers
Each main "Personal Folders" would have the options set to store stuff in it's own PST file.
Make sense?
