Don't panic. You don't need a new Mac. You need the last compatible version of Chrome.
https://dl.google.com/chrome/mac/universal/stable/gcem/GoogleChrome.pkg
HTTPS certificates for older Chrome versions sometimes fail if your system date is wrong. Go to System Preferences > Date & Time > Set automatically (Turn ON).
Don't panic. You don't need a new Mac. You need the last compatible version of Chrome.
https://dl.google.com/chrome/mac/universal/stable/gcem/GoogleChrome.pkg
HTTPS certificates for older Chrome versions sometimes fail if your system date is wrong. Go to System Preferences > Date & Time > Set automatically (Turn ON).