Am I a bad person?

My brother is mentally unstable and hasn’t wanted to see a therapist (always making excuses, he has no money, covid, etc) I have always been here to listen to him. Most of his problems stem from bad relationships with my mom and my brother so he often says thing to me about how evil they are. I am 7 weeks pregnant and I don’t think I can take his venting anymore. It stresses me out and I don’t want my baby to feel that stress. I’ve had anxiety attacks before from all his venting. I don’t know how to tell him that I can’t stress because of the baby. Am I a bad person for not wanting to help him out anymore?