I am so very sorry that you and your darling children are going through this. Lyn is right on with her advice as always. A wise lady she is.
Evidence is growing that trauma-focused cognitive-behavioral therapy (TF-CBT) is an effective treatment for sexually abused children.
In cases where abuse is documented, treatment may need to target symptoms of both OCD and PTSD.
Please consider using all your resources available in choosing a Child Psychiatrist. I hope you have a personal therapist for you too.
Be brave and you are in my prayers. Keep posting and we are here to support you. Gentle Hugs.