What do you do for a living Marie? Do you work, go to school etc?
You say that you feel like you can't do anything about it. But you are the ONLY one who can do anything about this. You have to get angry at the fact that you are feeling this way and decide that you don't want to live like this anymore. You have to FIGHT the fact that you do feel this way and rewire your thinking. Giving up and giving in to the anxiety and panic is only going to reinforce the loop of panic and reassurance you are stuck in. It takes hard work, and mental discipline - but you can beat it. If you really, REALLY want to.
I think at this point it's important to realise, that yes, you may not be able to get in to see a counsellor for a year, but there are still many things you could to do help yourself and your anxiety in the meantime.
You are pinning all of your hopes on this therapy, but the therapy is so far away that you have to consider other options to help yourself get better.
As I mentioned in one of your previous threads, I still highly recommend getting a hobby that you can totally immerse yourself in. Was there anything yoy always wanted to learn as a child but never had the chance to?
You are the one who has the control over this now. You've had the tests, MULTIPLE tests - you don't need any more. This isn't about lymphoma, it's about your anxiety. You have the control over how you choose to react to that. You can either panic and reinforce the spiral of anxiety and reassurance. Or you can think to yourself. 'This is my body trying to trick me, i need to rewire my thinking. I have had the tests, professionals tell me I'm healthy. So I will choose to be healthy.'
If you haven't already, read Pan's sticky on accepting the diagnosis.