Hello! I'm Jia Peng, and I'd love to give you a hug and chat with you.
From what I can tell, it seems like the boy might have an avoidant attachment style. This means that he might be more comfortable with strangers than with people he knows well. It's a way of protecting himself from feeling hurt again, which is totally understandable!
It's so sad to see how his current behavior is a kind of "revenge" against his loved ones. It's as if he's achieved his goal of making you sad, upset, and confused, and he's started this series of behaviors as a result.
It would be really helpful to get to know the boy's best friend, who usually gets along best with him. Could you ask them to stay by the boy's side, listen to his inner voice, and of course seek appropriate psychological assistance if necessary?
You mentioned in your question that the parents divorced when the boy was just five years old. I can imagine that must have been really tough for him. According to Erikson's personality social development theory, five years old is the beginning of school age, and their main goal is self-confidence and the need for interpersonal interaction.
At this time, the parents' divorce unfortunately led to some confusion in the child's understanding of relationships. Afterwards, he felt that all relationships were unstable, and things went from bad to worse. Now, you can use the boy's friends to get to know him better and try to help him.
I really hope this helps, but I also think you should read "Give Your Child a Sense of Security for Life." It's a great book!
Wishing you all the best!


Comments
We should start by establishing a gentle and nonjudgmental line of communication, showing him that we're here to listen without any expectations or pressure.
It's important to encourage professional help from a psychologist or psychiatrist who can provide the support he might need. We can offer to accompany him to appointments if that would make it easier for him.
Perhaps we could suggest engaging in light activities or hobbies that he once enjoyed, as a way to gently reintroduce structure into his life without overwhelming him.
We must ensure he knows that no matter what, our love and support are unconditional. Creating a safe space where he feels comfortable expressing himself is crucial.
Building trust back up is key; we can spend time with him, maybe have meals together or just sit with him, letting him know we're present and available whenever he's ready to talk.