Zend certified PHP/Magento developer

Spambot registration on Magento 2 website

my magento 2.2.3 website is over run by spam bots. the registration of fake users are through the roof and i need to have these stopped immediately.

I have google recaptcha and email verification for every account opened but yet there are still lots of intrusion to my registration with lots of fake email registration…
any suggestions on what to do?