Hi confused
Are you still living at home?
I understand that why you don't/can't say anything about this to your mum, but you can't go on like this, having to see this thing all the time, never having a chance to move on from what has happened, it is no wonder you are dealing with anxiety issues, or that you have struggled to move your life on from childhood... It is such a massive secret to keep.
You can't talk to your mum you have said, you aren't ready, what about your dad? Is there any way that you can speak to him?
I agree with the advice to contact a helpline, you need some specialist advice here... You are vulnerable, and your brothers will pick up on that, you need to protect yourself from them.
Some things you need to know and repeat to yourself.
Your child will not be removed from your care because you disclose abuse
You are in no way responsible for them abusing you, you did not accept this, ask for it or invite it into your life, you were abused by two people who are supposed to love and protect you, any fall out within your family from this will not be your fault, but the two men who have abused you, their actions, not yours.
You can get through this and become the person you should have been had you not had to deal with this terrible thing happening to you, GCSE's, work, career, relationships... They are all achievable things when you are ready, right now you need to stop feeling ashamed of what you didn't do and think about the things that you have done, and feel proud.
You have survived an abusive childhood
You are a mother to a loved and cared for child
You are a lovely and caring person who, despite being hurt so badly, still tries to protect her parents from the truth of their children's behaviours.
Coming to terms with abuse and the betrayal is hard, very hard, for me it was the struggle understanding why I wasn't loved and protected as I love and protect my child, for you it will be something different... But it changed my life, having counselling and understanding my past, and I have no doubt it will do the same for you.