My DT2 is 6 and is very sensitive at teh moment. If he gets angry with DT1 or DT1 shouts at him he bursts into tears, runs to his room and says to leave him alone. Half an hour later he is fine.
I have tried talking to him but am now lost for ideas as to why he is suddenly doing this. He has had colds and a sickness bug a few weeks ago, but I don;t think it is this.