Big hugs to you. I have a 17 year old son too, and yes it is not so easy. I've led a reasonably healthy life, so I have no idea where cancer comes from except it's there, I'm the right age for it, and now it's time to get rid of it. As far as stress and worry goes, it does not cause cancer by itself. It's good to keep stress under control though because life is so much easier, and it's easier to take care of yourself when your not worrying about other things. Take care, and I hope you have lots of support from friends and family in whatever form it takes. Have you got a breast care nurse to talk things over with? They can be very helpful.
Meg XXX