Firstly I'm sorry you're dealing with all of this. Besides a rather rampant case of HA, you have a family situation that's far less than ideal and causes additional stresses in you life.
That being said, there's something very interesting in your post. Marie, you post almost daily about your fears. Despite reassurances from members, doctors and tests, you can't seem to break free of the grip anxiety has on you.
However, your Mom throws up her hands and starts going along with your fears and guess what?... All of a sudden you're the one reassuring yourself! You're the one saying the rational things that everyone else has been saying all along? Coincidence? I think not.
I have to be honest, there are times I've read threads from members that are fixated on a disease and nothing anyone says, nothing a doctor or tests say will reassure them. I'm tempted to do just what your Mom has done and agree with them. "Yep... it's "pick your disease". Dr. Google is 100% right! Ohhh sweety, I'm so sorry to hear this "
Obviously, that's just mean and not what the forums are intended for but it makes me wonder if that approach would yield the same results. Would it be enough of a cyber slap upside the head to awaken the rationality that is buried behind the fear and anxiety?
So, as everyone has said, you can choose
to believe the irrational part of you that keeps sending you into the spiral of fear or you can choose
to believe the rational part of you that knows deep down you're physically fine and begin to work on what you know deep down to be true.