Step son was found and moved in

In December I made a post about my husband finding out his son hadn't been living with his mom and had been missing for months. He's only 14, almost 15 now. His mom had been the one texting my husband pretending to be him and pretending to be mad at my husband like it was the sons choice to not talk to him. When we found out and found out he's the mom hadn't called the police since he's been gone we flew down there to go to the police station. My husband fell into a severe depression and didn't come down stairs for Christmas. They opened a CPS case on the mom and she was saying how much of a liar my step son is. They found him the end of January. He was living in a trap house. There's so much going on. He made some allegations against his step dad but won't talk about where he had been or how he came to living in a trap house. We got emergency custody and he's holding some resentment because he said he tried to call my husband. My husband had gotten a new phone number and texted it to my step son's phone but my step son has been gone by then and never got it. He's not understanding that and thinking we weren't there when he needed us. He's in therapy and we start family therapy next week. My husband is really heart broken because he worried every night about him and now that he's back he seems to hate us and just stays in his room.