Fix Hostinger Nullroute WordPress Issue

My Hostinger account has been null-routed because one WordPress domain is spiking CPU, memory and process counts. I already know exactly which site is responsible and have tried the obvious fixes—disabled... (Budget: ₹600 - ₹1500 INR, Jobs: Cloudflare, Linux, MySQL, PHP, Technical Support, Troubleshooting, Web Hosting, WordPress)