HELP PLEASE!

I have a huge popular personal website, 260 odd pages which I edit using software installed on my home computers.  Its at www.roblightbody.com.  The creation of the menus and the navigation is all automated so that I don't have to think about it.  A godsend when you're dealing with such a big site, in a very small amount of spare time.

But surely, in 2008, things should be very different?  And indeed they have to be, be because my software is no longer supported.

• I want to be able to create and manage it online. 
• No software on my computer required at all. 
• But I still want it to look like a straightforward website. 
• In a few minutes, I need to be able to create a brand new page with text and photos and links, add it in anywhere on the navigation tree i like, and hit save and it to look after the rest for me. 
• Its also going to have to put the pages in the same folders and with the same names as before, since my website is *heavily* indexed by search engines just now and i don't want to lose that.

I've investigated various options but not come up with anything workable.  There are various CMS systems out there, but they're not aimed at static information-only websites like mine is.