WordPress SEO updated, high ressources usage

Hello,

yesterday, I updated the plugin WordPress SEO by Yoast and since that moment, my server ressources are at 100% and my website is down. I worked with my host support but they just blocked the access to the plugin.
This morning, I tried to activate it again with files from my another website and I noticed that it’s just when I click on “activate” that the page loads and the server ressources go high.

I did a screenshot of the Cpanel :
http://image.noelshack.com/fichiers/2015/15/1428319193-cpu.png