Thanks for your help. I was just trying to install a bunch of plugins suggested by 
SEO Power but I haven't activated them yet. The only active plugin is 
SEO Power. Got suspended in the middle of installing them. Maybe it's the installing process not the plugins themselves that cause high system resource usage as they are not yet active. 
Weird thing happens. My addon domain is gone. When I tried to add it again, I got 
"There was a problem creating the addondomain.     
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              Error from park wrapper: manageyourdiabetesnow.com is already configured." Could you help please. Thanks in advance.
                           Error from park wrapper: manageyourdiabetesnow.com is already configured.