Blog disaster

I managed to do a very stupid thing yesterday. Many beautiful backgrounds have been appearing on some of the blogs I read. There are a number of talented digital artists making the backgrounds available for free. After some research I found one I really liked and hadn't seen on another blog. After reading instructions for changing to the new background, I boldly uploaded it. BIG MISTAKE!! My blog is 3 column, something I did myself using instructions from
Tips for New Bloggers. But, I didn't save before I tried to change the background. My 3rd column was gone and the new background wasn't even visible! I have a little(stressing little) knowledge of html so I went back to Tips for Bloggers and tried to follow instructions to redo the 3rd column. It kept coming back with an error about not recognizing "Newprofile". I took a break, went to the grocery store, then had lunch. All of the widgets I have on the outside columns are making the html very long so I decided to delete some. Probably not necessary, but I felt like I was doing something. I saved the codes to notepad. Took another short break. Started over. This time I previewed after every change. Going well til the last change. It is supposed to move the about me profile to the new column to set up the layout for the ability to add other things to the column. Trying to think logically(not easy) I decided to remove the original code for my profile. I copied it to notepad before doing so in case I had to put it back. One last preview and YAAAAYYYYY! It worked. Then another hour adding widgets back in.
Last night I used the new background to make a new header but I am not fooling around with the rest of my layout again.