I am sorry that you had to endure this uprooting of your life to come to America and then be mistreated this way by your spouse and his family.
Needless to say that you aren't the first to go through this and you definitely won't be the last but there are ways to overcome this. Go to your interview and be as honest in your answers as possible.
Truth gleams through and when people are genuine in their replies, the officer can usually tell the fake from the reality.
The lawyer step I believe has passed already. The lawyer in the interview is useless since only you can answer the questions the lawyer can't answer them for you. As for evidence you only can show what you have. So you can show them text messages, FB messages before, during and after the marriage or whatever you have. Emails if you have any. Anything from the mail that you were getting at the claimed marital address that proves you were living there and so on. You need to go with confidence, tell the truth, explain how and why the marriage ended. Show some tax returns if you have any. I had a waiver interview after 4 years from filing and it was fine, lots of questions, but it went good.
