Cpu usage high


I currently use a hostgator business plan server also bought an ecommerce theme from themeforest and recently i make site. My visitor does not come to the site yet, whenever the Visitor gets 4 or 5, the CPU Usage becomes 100% along with Entry Processes and I/O Usage. If no visitor come, Then it also shows 100%. When it gets 100%, Database shows Establish Error.
The work i have done for Solving the Problem..
• Jetpack by WordPress.com
• Akismet Anti-Spam
• Wordfence
• Caching plugin
2. From Some days, using Droplet 2 VPS from Digital Ocean, But the same result Again Showing.
3. Besides, I uninstall all the plugin themes and delete the data base, again installing the WordPress and keeping the default theme activated for 3 days, but the results were the same, the CPU Usage was 100%
4. For a while, i just keep one indix.html file, then again re-install it. But the Same Result Happens.
5. also tried blocking Bad bots via .htaccess
However, after installing the WordFence Security Plugin, I have seen some problems, some visitors from various IPs have come from different countries, but they do not show the Google Analytics and the link that is not linked to my website. The type such as Visit my site, by creating link using some random keyword. And Per minute 30-40 hits to my site from different IP/Country. When I block those, then uses another IP. It run Continuously.
To be Noted: Another Website Running Using the same Server where Visitors 200+ and CPU usage only 2%
My server configuration
1. php version-7.0
2. max_execution_time – 360
3. memory_limit – 264M
4. post_max_size – 64M
5. upload_max_filesize – 64M
Now what I have to do? Give the Exact Solution that will surely work to solve the Problem Permanently.