Sorry to hear about your experience and certainly children should never be exposed to things beyond their comprehension - at aged 2 or 9 years! It took me a moment or two to digest what you have written and certainly if I were your counselor I would feel that this is important to disclose to them. If they are a positive person for you, this should be received with empathy and understanding.
I cannot imagine what it has done to you, but certainly its worth bringing this up with those responsible for regulating baby-sitters (if there is such a thing), to prevent others from being similarly affected.
As with Dr Paul, I hope that you overcome this and move forward.
Dr Dinesh