Disconnected,and terrified

My husband is great...however his sons from his previous marriage are awful human beings.In laws say it's all the ex and her influence.To be honest,yes,she is a wretched person(lies,cheats and stole from grandparents).She constantly tries to manipulate hubby,(he barely speaks to her)and lets the kids run wild.The kids are terrors.The school calls constantly,the kids are late, ditching, bullying and now threatening the guidance counselor,who is legitimately scared because after stepson#2 threatened to shoot a classmate,the police found a gun the kids had access to.We never found out who's gun it was(mom or her live in boyfriend,with whom she has 5/6 month old son by).Hubby told ex last year, get the kids help,as they had attacked my kids,stole money,were sneaking porn,and pot, and when caught,attempted to physically their father.They purposely lied about their father to my family,so that family questioned our relationship,told the grandmother and aunt(husband's family)that he ignored them and only paid attention to my children and I(so that in laws would lecture is, after taking his sons and spoiling them with gifts,then demand hubby give his sons one on one time),they called their mother and told her we were trying to conceive,that hubby ignored them,or was abusive.Now,we are pregnant, and the tech suspects a boy... I am terrified. I can't seem to connect to my unborn baby.... I am so scared it will be a boy, and be like hubby's older sons. It's the worst feeling. My husband is so happy, he loves being a dad, his older boys break his heart. I can't get over the fear of this baby being like the older two. I tried to be good to his boys, treated them like my own, and they enjoyed hurting my family and I, almost as if they were trying to hurt their dad by using us.