Old data crash. new data have diffrent url. Google seo help needed

Hello All,

I have downloading site and I am getting 50% of traffic from google. But few days ago my server is crash and I lost my all data and script.

Now i am using diffrent script and data which all url structure is difrrent from old script.

Now please tell me what should I do so i will not loss traffic from google. I want maintain my raking in google.

Thanks