Sudden Comment Overload

I manage a site that is having a sudden explosion of comments. All are valid, so not a spam problem.

Problem is that the comments are (I think) overloading the database server on the host. So visitors are getting a lot of 500 errors (database connection, timeout, etc).

Visitors are leaving comments, and also scrolling through existing comments. Again, not spam, but valid comments (tributes/condolences on the passing of a public figure).

I have installed a caching plugin for the static pages, but I think that a ‘comment caching’ solution might reduce the 500 errors that visitors are seeing.

Will your plugin help with the above issue?

Thanks.