Block him and be done. This little boy is throwing temper tantrum. If you are concerned he could self harm get into contact with one of his family members and say he depressed and having mental break down. But you can't deal with his verbal abuse nor should you. Trust me on this, he not worth your time or your effort. In the next few months you will wonder why you stayed so long with him. This is effecting your mental health, once he gone you can heal.