What are the expected litigation costs and risks for filing a copyrights infringement?

I worked on a software project for a client under the given assumption that he would pay for my services two weeks into the project. There was no contract presented or signed but I trusted the client so I started working. However, the client later revealed he didn't have the financial means to pay me. We tried to find a working compromise but ultimately we couldn't reach one and I was let go after 4 weeks of unpaid work.

As I didn't sign a contract releasing the copyrights for the code I wrote, I filed a DMCA notice(https://about.gitlab.com/handbook/dmca/) to get my code removed from the project. The client filed a DMCA counter notice to cancel my removal and according to the company hosting the project I must start litigation and send a court order or a subpoena.

I did some research and as I understand it, I must first assess the expected costs for proceeding, the risks and the chances of success are.