[immibis]

You could start by subpoenaing the registered holder of the IP address.

In general, you can ask a lawyer for your options. Chances are good there are more than zero. But only if you can afford a lawyer.

If you're getting scraped from a country where you don't do business, you can block the country. It's not good to block a country, but it works as a temporary measure. If they really want your data, they will move to a country where you do business, which means a country where you can get a lawyer. Assuming you can afford a lawyer. If they're using rotating IPs, likely some of them are from your country. You might show a judge: "Hey, look, we're getting so much traffic, from a wide variety of IP addresses but it all seems to be the same person on the other end, which would make it illegal DDoS. Can we trace back some of these?" and if you're lucky, the judge might say yes.

DDoS is not a relatively trivial matter.