I have made a video to demonstrate what I have to put up with every day.

It was suggested by Orange Website that the fact that my disk usage is getting high might be a factor

“We could find that the disk usage of your account is 83%. Also, your account is hacked, please restore the account from the jetbackup available in cPanel. Also, change the cPanel password to a strong one. Please keep the plugins and themes updated and remove the unwanted plugins also. “

Two things I would point out is that:

• The problem’s onset was not gradual but happened overnight after leaving the machine on by mistake
• My disk usage was even higher but that never made any difference to the speed of the site.

I have had the suggestion of trying something Orange Website offers called LiteSpeed WebCache Manager.

I shall try that and see if it improves things.