Are they actually targeting you personally? I find botnets go around targeting small hosting companies to practice or casue problems or look for holes because big hosting companies have the funds and infrastructure to easily protect themselves against botnets. Many are also trying to break in to hold the sever random. Running a hosting company is difficult and the botnets make it even more difficult.

Maybe it's a competitor but there isn't really ant competitors other than twitch and kick. I doubt they would do that.

Hope you can find a solution.