A "look and feel" is actually a "template_look" object. Could you have deleted yours, I wonder? You should be able to see it listed as a subitem by visiting your admin site with "/design" at the end. If that's not it, you could try turning on debug output for the admin siteaccess and see what wisdom it provides.
You can do a "create here" in /design, but first you'll have to get the "template_look" class to appear in that menu, as generally that's not desirable. Go to setup, classes. "template_look" is under the "setup" group. Temporarily add it to the "content" group and it should show up in the drop-down list of objects you can "create here" (if not, clear the cache).