I am using the Journalist theme by Lucian Marin, and I also have similar problems. Instead of 2 columns it changed to one column, and the header bar is overlapping the title of my blog post. As well, I haven’t changed anything. Any ideas?
I had a look at your blog, and I think that if it has only been today, just give it some time. Sometimes these things happen because the mods are fixing something. If it doesn’t fix itself in more than 24 hours, contact support.