Retainer for Lawyer to help for Sewage Backup

So a sewer main collapsed on the street outside my house. That caused all the sewage of the apartment building across the street to back flow into my basement. This started about Jan 13, I contacted DEP and by MLK Day, a supervisor knew there was a collapsed pipe. For 3 weeks I had to call 311 to file a complaint to get DEP to pump the sewer to try and keep the level of sewage down in my basement. My house smells like shit, There is still sewage in the basement. I use a sump pump daily, some times renting a second sump pump. 

It was just 2 days ago that DEP got a contractor to replace the sewer line. After talking to the crew, they will not get to my house until next week.

I had a company estimate and a full clean up, which includes removing all 30 years of memories in storage, washer and drier, and stuff like that, all put in the garbage, then the basement DECONTAMINATED, then placing air scrubbers in the house to get the smell out. $26,000 (minimum) Home insurance has a cap of $5000. 

I need to have a lawyer help me file a claim and this is for the retainer, especially if they do not settle, I need this to go to court. 

The initial money went straight to the beginning payment of the retainer, I need another $8,000 to pay for the minimum if it goes to trial.