I would reccomend therapy. You need to deal with what happened and a therapist can help you do that. What he did to you was wrong and it wasn't your fault. Your mother made it worse by forcing you to keep quiet about it. She is just as wrong as he is. I hope you learn how to heal from this. Telling you boyfriend is a decision that is up to you. I think people are entitled to secrets, but you should learn how to deal with what happened. Your be isn't an expert in mental health and telling him may not make you feel better. It can be q relief though, to know you have someone to talk to about it. I wish you luck in finding resolution from these events that happened.