my draft mailbox has disappeared! Where did it go?

Contact Sophos. Seem they identified them as a virus/malware and quarantined them. You have to go through Sophos to read/recover them

NEVER allow anti-virus software to remove files from your computer, especially when those files are e-mail messages! Assuming the message even actually contains malware, removing it this way will corrupt Mail's mailboxes and doesn't properly remove the message from the server under certain common conditions. See:

How to remove infected files

As for how to solve the current problem, I'm a little unclear on exactly what has been done. It sounds like you may have removed the Drafts mailbox yourself. If that is the case, and if that mailbox is still intact, you should be able to quit Mail, then put the mailbox back where you removed it from, replacing any newer Drafts mailbox that has been created. If that doesn't work, import the messages it contains (in Mail, choose File -> Import Mailboxes).

(Fair disclosure: I may receive compensation from links to my sites, TheSafeMac.com and AdwareMedic.com.)

Remove the worthless Sophos product by following the instructions on this page, and also this one, if applicable. If you have a different version, the procedure may be different. Never install any "anti-virus" product again.

Back up all data before making any changes.

From the Mail menu bar, select

File ▹ Import Mailboxes...

Choose Apple Mail as the format and import from the mailboxes in the folders you moved to the Desktop. The imported messages will appear in a new mailbox. Move the ones you want to keep wherever you like and delete the rest. Then delete the folders on the Desktop.

You seem to have tried to restore the messages in Time Machine. How did you do that and what happened?