I understand your fear. It's paranoid - paranoia is irrational fear; but yours is normal and understandable.
I have fibrocystic breast disease and I understand the pain/tenderness. I also understand how often a mammogram comes out "suspicious" (or any other word they use). I understand that monthly self exams are pointless because you are already so lumpy, so it's ridiculous to check for lumps which, by definition, are already there.
I also have had a number of biopsies of different types. That's more waiting. It's agonizing. But ordering a biopsy doesn't mean you have cancer - it means it's another tool to let you know there's nothing there. That's so much better than "wait 6 months and come back and we'll see."
But almost all of the time, it's nothing. Yes, they have to be careful. They also, frankly, have to order a bunch of tests because, if they miss something in a very small percentage of cases, it's a lawsuit.
The diagnostic techniques are very good. Having options is a good thing.
I got rid of my cysts 5 years ago and I am starting to get used to not having those call-backs and worries. All I can tell you is, the worry accomplishes nothing except make you stressed out. Please try to go easy on yourself.