Website security issue

Hi;
I have an issue with my server for some reason the memory and storage resources get exhausted, and then the server crashes.

I did not have this issue in the past i actually started having it since the trial version of Cleantalk was expired.

I had to get new server and i migrated everything to the new server, after relaunching again the main site i have the same issue on the new server.

I have already have a support plan from CWP Panel on centos server.
it seems there must be some issue on the opencart website that causes the problems of resources overload.
the website is xtrasoft.eu
I don’t mind giving you access to my server if you could investigate what is causing the problem
There was something i noticed yesterday all my index.php and .htaccess were set as 775 which is not normal i modified everything to 644.

but i still have the issue of exhausted resources on the new server
best regards

The page I need help with: [log in to see the link]