Hi Siila,
finding out about having an AN and having that yearly MRI check up really can be a stressful situation, I'm sorry you're going through this. Everyone's situation is unique and it is difficult navigating the information and options for next steps...For me the information on this discussion forum was very valuable to understand the process and options (I spent alot of time on research --some may say too much-- but it was also a way of coping at the time).
It may be worth asking your doctor if they can do your MRI without Gadolinium, as i recently discovered (after about 10 MRIs over the last 3 years) , that they can do the next one without GAD.
its really difficult to maintain peace of mind when you are going through this difficulty but anything you can do to reduce stress may help to manage somewhat (it sounds like you've started this with mindfulness practice)... i hope that your way forward becomes easier for you.
Stella