How can I get these false charges removed?

I divorced in 2010 because my marriage was unbearable. She went with her boyfriend to Mexico and left his 17-year-old son with me. Shee took my little 6-year-old son with her to Mexico in January 2011. She sent my little son in air international travel. The reason she gave was wanting to spend time with her boyfriend. I was detained when I went to pick up my son at the international airport in Houston, Texas and processed by immigration. They released me under the promise that I go voluntary to immigration court. I take legal custody of my 2 children and live in peace in a year, she returned, and fight with me for removed the child support. She came to my home one day and have a fight outside the home. I called the police. When they came the sheriffs ignored me. A policewoman contacted my ex-wife and she said that I hit her. I was not detained. Then months later under pressure of her, I arranged and modified, in court, the custody to remove the child support and now we live in peace. I have a appointment next year in migration court. My last appointment after 2 visits to the court. Now, more than two years after that fight I receive a warning from a friend that I have arrest warrant. I remove the arrest warrant and I have an appointment in a month in court. I need to know if can I get the charges removed. This affects my life in big way, especially in the Immigration court. I have never being detained and I never had any kind of legal problems, not even car accidents or traffic tickets. I never fight with anybody. I have all the court evidence, family and immigration, please help me.