I'm not sure what you mean when you say you need help to "build" a case. Either you have one or you don't. Call your local Bar Association. They Wil have a list of volunteer lawyers or lawyers that will provide pro bono or "po bono" (reduced fee) services. Good luck to you.
Prior counsel has it correct. Either you have the facts or not. If you're speaking about documenting your case in connection with the REAL ID requirements, then you're on to something. And if you want the best presentation of your case, then don't skimp on hiring counsel.
My colleages are accurate in their comments. Most law schools have immigration clinics that may be able to assist you if you cannot afford a private immigration attorney. If you are an F-1 student, your education institution may have an international student department that has a list of qualified immigration advocates - attorneys or BIA approved agencies. Good luck.
Legal disclaimer: The statement above is provided by CC Abbott is based on general assistance and not intended to be a legal opinion because not all the facts are provided. The person requesting information and all others reading the answer should retain an attorney who is permitted by the state bar within the jurisdiction who can examine the complete facts and provide a legal opinion on your case. All information provided in the above answer and other information provided by CC Abbott does not create an attorney/client relationship within any state of Federal law.