External Reversed Proxy

Hello, I've issue with DDoS attacks so I decided to use reversed proxy to protect my origin server and it forwarding all requests to my origin server. And I want to use it as shared ip for my websites. I've changed it from Basic WebHost Manager" Setup, IP Migration Wizard. But now all websites are showing the default page SORRY! If you are the owner of this website, please contact your hosting provider: xxx@xxx.xxx It is possible you have reached this page because: What should I do to fix this? The new ip is already forwarding the requests to the backend ip. Now I need to use it as the shared ip and I'm facing this problem.