Please, please help! I think I’ve lost my categories!!!

I’ve never really properly understood the difference between categories and tags. Up to now, I have just used categories and just ignored tags which I thought were just a way of assigning keywords to a post.

I used to have a category/subcategory structure that was largely geographically-based… you can see what it looked like here:

http://216.239.59.104/search?q=cache:VIsaRIaouOMJ:www.aluxurytravelblog.com/+site:aluxurytravelblog.com

Looking around the admin interface, I noticed the category to tag converter. I assumed that if I had a post under, say, my France category, that it would add the tag/keyword ‘france’ to all those posts. I therefore thought I’d apply this to most of my categories but I now realise that the categories are not retained during this process… they’ve GONE!

And now I’m just left with the categories at http://www.aluxurytravelblog.com/

This is terrible for me. Over 100 categories lost! Is there any way I can reverse what I’ve done? I think it’s been a couple of weeks since I last took a back up…

Thanks for any help,

Paul