Cannot use System Settings to make any changes; Unity seems "broken"

While I was running Ubuntu 14.04 LTS, it locked up on me, and I did a hard reboot. (I had to reboot by physically holding down the power button.)

What happens now, is my wallpaper, my icons in the Launcher, my theme -- it is all gone.

I am also missing stuff in my Launcher that was there, and there are icons there that I didn't have there before (or that I had removed when I started customizing). I am back to the default Unity theme.

But it's more than just a missing theme. As I say, the items I had in my Launcher are missing too. Some of these are a
real problem because I installed them through the Software Center, and so I do not know the Terminal command for them. And customizations like auto-hiding the launcher are gone, too. International keyboards that I had installed are gone.

Ubuntu now ignores any setting I try to make with Unity Tweak Tool. I mean completely ignores. I am also unble to change theme or any other aspect of appearance using System Settings.

When I try to auto-hide the Launcher using System Settings, it will not let me slide the swtich from "on" to "off". If I try to enable workspaces, the little checkmark next to "Enable workspaces" disappears as soon as I let go of the mouse. Same applies to "Add show desktop icon to deskbar".

And there is one more piece of weirdness. In the login screen, I have my wallpaper, custom icons, etc. (but not the keyboards). Once I log in, then it there are the problems that I have described.

I am open for any suggestions on how to resolve this. I would like to be able to use System Settings again to change wallpaper, etc.. And I want to restore the missing icons from Launcher. If possible, I would like to restore all settings the way they had them. But most of all I want System Settings and Unity Tweak Tool to work again, of course.