HELP! RSS Breaks Everything!!

Argh!!!

I’m trying to create a complete RSS feed for my blog. Unfortunately, it’s over 2000 entries! When I set the RSS syndication options to 2000, not only did I not get a feed, it seems to have frozen my entire administrative panel. I can’t get in, not even to change the options back.

Is there an actual file I can edit via FTP to change it back to 12? How do I fix this??

Also (but less pressing), can anyone recommend a better way of getting all the entries in XML format?

Thanks!