Child custody

My ex and I who were never married have joint custody and I have primary placement. He is court ordered to pay child support, healthcare expenses and insurance. Concerns: he is behind on child support payments, has never paid for health care expenses and failed to provide insurance for over a year. He was a drug addict who went through rehab. I suspect he is on drugs again and fear my daughters safety. She asks to not go there and he has not seen her in 6 weeks. When she visits him she's stays in a 2 bedroom trailor with 5 other people, has no bedroom and sleeps on a couch. She expresses her dad takes her on car rides to meet people to sell guns. He was recently fired and has no job. He's recently charged with domestic abuse and a permanent restraining order was placed. What can I do? I believe he is in contempt of court by not following orders.How can I prove drug use and dangerous lifestyle. My husband and I give her a safe stable life and I want to keep it that way.