Recently i made few changes to my magento store installed new theme and configured well. It was working great and loading time was even superb but after few days don't know what happen my stores taking 30sec load.
According to gtmetrix Page Score is 95% and Loading time is 30sec. Can anyone tell me what's the issue ? Here's the URL - http://www.smnutritions.com/
Try following things
1) Try to revert back to old theme and check the load time. If load time is less compared to current load time then you have problem with the new theme.
2) Notice the following screenshot taken from gtmetrix.
Notice the wait time 23.89s it is to much for an ecommerce site.
As mentioned above the gtmetrix Page Score is 95%, so I believe that your site data loads properly. But some JS file taking long time to be ready, which may happened because of your latest theme.
I would suggest you to compress your site data, so that even multiple JS files will take less time to load.
Try to install standard magento on the same hosting and check the load time, if it 's still slow then the problem come from hosting, unless the problem come from your magento extensions/customize.
As per your post website performance slow down because of changes done recently therefore most probably it is related changes
and not with hosting.
Most website provider inform in case any maintenance or server down or slow because of some internal issue to clients via emails.
My website speed sometimes 4 seconds and sometimes 8 seconds on GTmetrix