@riss81
Hold on!! It’s scary, it’s how many people react and it’s not going to happen!!
Your medical team actually know a great deal about this stuff. While you never planned it, you’re going to learn a great deal more about it too. As you say, caught early, always good and your medical team won’t waste that advantage.
It’s natural to worry about it spreading although quite probably you didn’t have a clue until diagnosed and felt fine!
Lots of us have known how you feel. Lots of us are still here, living our lives and scratching to remember some bits of the story! Things get better when you know what your treatment will be, when it will start and you can start to feel some control again. Until then, deep breaths. Sit in the fresh air, do things that remind you that life is unpredictable but amazing and that you are in good hands. Have a good cry if that helps. But find some occasions to laugh too, even if it’s a fraction hysterical. You will get through this. Best wishes.