I would think knowing would be half the battle. Once you know what you’re dealing with, you can then work on ways to… well… deal with it. As far as ‘confronting’ your mom, go ahead and have a talk with her about it, but in a non-confrontational way. No reason to go into it expecting it to be unpleasant. As a mother myself, my best guess is that she was trying to protect you by keeping you in the dark. Misguided, yes, but probably with good intentions. Good luck!