How to diagnose the problem of long page loading when connecting an SSL certificate?

Question

ubuntu

When connecting a certificate from godaddy, friezes began on the pages. Every time it loads for 10-20 seconds, after which either the page still loads, or ERR_CONNECTION_TIMED_OUT.
The server works like this.

This is how the page loads.

The problem did not start immediately after connecting ssl, but when attendance became > 100 online.
The problem is already within 5 days, if you disable ssl - the site flies.
Help with advice on diagnostics, or tell me where to dig if there is an experience of similar problems.
UPD: server at digitalocean, LAMP + Ubuntu
UPD2: switched to nginx - the problem is gone, thanks everyone!

Answer 1

nginx.org/en/docs/http/configuring_https_servers.html

Answer 2

Set up OCSP stapling. And caching ssl sessions for clients.
(on nginx it's really easier to do).
Well, yes - the ssl handshake locks the web server workers, so they may simply be missed.

Answer 3

Hire an admin, your problem is clearly not typical, on Apache it should fly no worse than nginx