Buy a folder with lots of pockets and get print outs of all your tests. Ask everyone you see to give you a card with contact details. Put a diary and a notebook in that folder and treat it like your new best friend.
Take your trusty folder with you to each and every appointment. This stuff can take years to sort out (sorry, but it can) and it makes it so much easier to keep track of who, what, when, where and why if you start keeping your own set of records right from the start. That way, if you are asked any questions about the afore mentioned 5W's, you have access to the info.
Thing is, we all forget details. Services don't always communicate well with each other and it is very frustrating to not have answers when someone asks who your surgeon/oncologist/rad onc is, when the last test was, when your next appointment is etc..
I've been through this a couple of times and have learned that while my anxiety never goes away, I can make one thing easier to manage--keep a really good project management folder.
Good luck, AA. Marg x