My ex is trying to intimidate me. I go to court in two days and I am worried he is going to make up lies.

My ex has full custody of the kids and I am trying to get my visitation with my kids. I am very afraid that the judge will believe him and I wont be able to see the kids. All my kids say they want to see me every other weekend but he wrote a letter saying the kids don’t really want to see me. I don’t know where to turn or what to do. I don’t have the extra money for a lawyer. If someone can please point me in the right direction, i would really appreciate it.