Site drop in search results after attacks?

Question

DDoS Protection

Hello, I've run into a problem. That after massive attacks on the site, it falls in the search.
I have 80+ sites for each city. After bot attacks on the site, it falls in the search, let's say it was stable 50-60 people, then sharply 1-5 per day. The attacks stop. Sites on WP, put a bunch of plugins on protection, we ban bots, new ones appear. We know exactly who did it, but we can't prove it. They have already lowered 5 sites, now they will take on others.
Sites work stably, there are no failures, the load on the server is always normal, the load on sites that are under attack increases slightly, but the site works fine.
They closed access via htaccess to almost all sections.
Who faced this and how to deal with it? This is my main income
On the screen, this is only a part, they hammer on different pages of the existing site and not from different countries and IPs.

Answer 1

Contact a qualified professional.
If you "had consistently had 50-60 people" - this is so hot what a load.

Answer 2

Dolby from one IP will save the limit of simple in nginx