Your mom is also dealing with the fact she wasnt there to protect you, she is fully blasted with this herself. I went through a VERY similar situation, comes out at the most strangest time. I told my mom, and all she could say was "he wont remember that." I was so hurt by her lack of concern and non chalant attitude. BUT later I found out it was because she felt she failed as a parent, parents are suppose to protect their children. So keep that in my mind. Ultimatley, if you feel you can not handle this situation in discussing this at home, find a counselor. You NEED someone to work through your emotions. Im sorry youre family or mom isnt there for you at the time you feel you need it most, but hang in there, you will work through this together at some point, its all a shock. Most parents or people cant beleive or wont believe someone can just forget such an event such as this, but you block you out, and youre memory somehow gets triggered. This is a revelation per say, and its a lot to swallow for everyone. I hope you will find the help you need to get through this one.
everything happens for a reason...beginning to wonder why.