Oh no, my template!!

I just accidentally overwrote my highly customized Blogger template, which made my blog look like part of my website. It had tons of custom images and my own navigation bar, and made everything look seamless...and now it is gone, gone, gone! I don't even have a copy of it or a printout of it! I have no idea how to modify the new generation of Blogger templates the way I had modified that one years ago, now that I've accidentally migrated to the newer Blogger platform, where everything seems to use more complicated scripts. Argh!! It may be time to retire this blog and replace it with the one I use more often, anyway... but I love the history of this one since it goes back to July 2001! I can't believe I didn't save the old template at all, but of course, I didn't realize I was about to lose it or I would have.