all in one how to deactivate, admin panel blank

Every few days my server cpu hits 100% and the site goes offline. This happened after I installed all in one seo.

this is what happened.

i uploaded the folder, activated the plugin, it asked for my server log in credentials and then the admin panel went blank.

I couldnt enter my admin panel.

I then had to manually edit out the plugin activated text in the wp_options table via phpmyadmin, and also delete the folder in my plugins folder for all in one seo.

But I dont think this properly deactivated the plugin. The site works, but now every few days my site goes down. I think theres still part of the plugin running on it somewhere.

what do i do to properly remove this plugin and try again?>

if i try to put it back on to try to deactivate it properly it brings down the admin panel..

PLEASE HELP!