I'm just now 12 days after surgery for my cancer. The other responses here are spot on. An expert could not give you a diagnosis on an internet forum. Docs and others based on experience can offer only conjecture and generalities.
It's very common to want some certainty as quickly as possible, especially when the possibility of cancer arises.
Regardless, do what your GP says.
Cope however we all do, but add this forum to your options. And best of luck.