high cpu load index.php wordpress(100%cpu)

I moved my site to a virtual private server(VPS) because my sharing web hosting account doesn't support the growing number of visitors, but when i install it, CPU spikes to 100% and the site doesn't load. please check these two screenshots http://ift.tt/1xDcTUc http://ift.tt/1vVzIwo

I tried everything; desactivating all plugins, deleting all plugins, checking database, installing a fresh copy of WordPress but still the same problem.

Plugins: All In One SEO Pack Attachment Pages Redirect Autoptimize Contact Form 7 Disqus Comment System HTML Javascript Adder iThemes Security No Image Link Official StatCounter Plugin WordPress Related Posts Responsive Lightbox WP-PageNavi WP-ReportPost Wp Pagenavi Style WP Smush.it WP Super Cache

i updated all plugins and wordpress

VPS centos 6.5 : 5GO RAM, 50GO Disk, CPU 2 vCore(2.0 GHz+)

Apache Version 2.4.10 PHP Version 5.3.29 MySQL Version 5.5.40-cll

number of visitors between 300000 and 500000

online visitors now between 200 and 300

Please someone help, i have been struggling for months to find a solution.