The problem seems to be that the alias between your user account stored in the SAM and your user profile stored on disk has been broken. (Your user profile is intact in C:\Users\YOURNAME; as long as the file NTUSER.DAT is not corrupted, all of your settings are safe).
The first thing you need to do is create another user account, with admin privileges (name it "temp001" or something to avoid confusion with your other account/s) and log into it. When in the "temp001" account, go to Control Panel > User Accounts and click "Turn user account control on or off"; uncheck "Use UAC to protect this computer" and click OK. Then go to Control Panel > Folder Options, go to the View tab, select "Show hidden files and folders", and uncheck "Hide protected operating system files" and "Hide extensions for known file types." Click OK.
Now, open up My Computer and navigate to C:\Users. Check to see if there is a folder such as "YOURNAME.001" (this would be the user profile currently in use). If this is the case, rename "YOURNAME" to "YOURNAME.OLD" and "YOURNAME.001" to "YOURNAME.001.OLD". Log out of "temp001" and log in as yourself. This will force Windows to recreate your user profile in the correct folder.
Log out of your user profile and log back into "temp001". Open My Computer and go to C:\Users. Rename the "YOURNAME" folder to "YOURNAME.NEW", and rename "YOURNAME.OLD" to "YOURNAME". Log out of "temp001" and log in as yourself. All of your stuff should be there.
NOTE: If you get an "Access is denied" error when you are attempting to rename the YOURNAME folder from within the "temp001" account, you will need to change permissions. To do this, right-click on the folder, click Properties, click the "Security" tab, click "Edit", click "Add", and type "temp001". Click OK. Select "temp001" in the list of users and groups and check "Full Control". Click OK.
When you are done getting your user profile in order, you can delete the "temp001" account as you normally would delete any other. (Leaving the "temp001" account without a password, and with permission to access/modify your files, may be a security risk.)