Can someone help with dream interpretation?

My boyfriend is very stressed because of a recurring nightmare he had when he was younger. In the dream he says there are two of him and the "bad" one kills his whole family, even the cat, while the good one can only scream and watch but can't stop him. He recently had this dream again except the new pets and his step dad were part of this one. He loves his family and it worries me because he never opens up but he did to tell me this. He thinks the only way to make the dream go away is to stop caring but he told me he didn't want to stop. He is so stressed and I wanna be able to comfort him with a logical explanation. Please help.