My aunt was in the exact situation as you with all 3 of her children, with dad gone. She eventually had to give them to dad for just a while, and turned out to be the best thing she could've done. She got the kids twice a week for dinner, and made sure she was in good mood. They just had a happy relaxed meal, no getting in trouble, and she found the boys started talking to her and opening up. Their relationship started all over again, but a positive one. She didn't discuss their behavoir, that was up to dad for a while, and the kids had a happy, safe, loving place to go to at mums house.Not sure if this could apply to you, but thought i'd let you know. SOOO many mums will/have gone through this. All the best for you and your family.