can't log to my admin

have you tried:

-deactivating ALL plugins temporarily to narrow down and possibly fix the problem. If the problem goes away, activate them individually (one-by-one) to find the culprit.
If you don’t have access to your admin area, try deactivating them manually via FTP or phpMyAdmin.

-switching to the default theme (“twentyten”) for a moment by renaming your current theme’s folder in wp-content/themes. The idea is to force WordPress to fall back to the default theme to rule out any theme-specific issue.

If you don’t have access to your admin area, then access your server via FTP or SFTP or whatever file management application your host provides.

– resetting the plugins folder by FTP or phpMyAdmin. Sometimes, an apparently inactive plugin can still cause problems (because the hooks remain unless plugins completely removed).