I am going through a custody battle right now with my soon to be ex. I never thought he would fight back and be so nasty. I am asking for sole physical responsibility and supervised visits until clean drug tests. We have hired a guardian ad litem which we are splitting the cost. So far she has been good and is gathering as much information as posssible. I had a ton of text messages and emails where he admitted to his addictions as well as family and friends who were able to confirm his suspicious behavior throughout our relationship. As others have stated, a journal is a good idea. It's a rough road but you will get through it. Just keep being that strong voice for your children and don't give him any slack.