I'd done the same thing with my blog's theme and layout - I feel like I had had my last layout quite a long and despite having fancied a change for a while, I was never quite brave enough to 'just go for it', in case I missed my old theme and then proceeded to waste hours putting it back to how it was.
But yesterday I decided I was going to take the plunge - I loved my old blog theme, but I felt like I wanted to give it a bit of a modernisation, whist very much so still staying very 'me'.
So I kept my blog's logo/header and I've kept the same sort of color theme, but I've given it the modern sort of upgrade/change that I had wanted to. And I'm really pleased with it so far - there's still a few changes I'd like to make to it - mostly the image sizes, I would really like to increase the size of the images as I feel my blog is generally quite photo-heavy and visual, so I'm currently just working out how that can be done.
But once that's done, I think I'm going to really enjoy this new layout and hopefully you will too. :)