I'm glad I've been able to shed some light on what is a very confusing experience. You are correct in thinking that DCIS is contained cancer - still in the ductal system of the breast and not yet invasive into the breast tissue. It is believed that if left alone, it would most likely become an invasive cancer. The type I had was Her2+ but negative for oestrogen and Progesterone sensitivity. I have learnt so much about BC since I got ill - I wish I had had the luxury of time before having such major surgery, but I had 13 days from diagnosis to mastectomy and I spent most of that time crying!
I'm sorry you've had a hard life but I'm very happy that you have supportive children who will be there for you through this experience.
Good luck with everything, and I am very happy to hear from you whenever you need a friendly ear.
More hugs, xxx, Jeanine