trying so hard to be 'fine' ahead of radiation

This is not a feeling that is helpful, but often cancer stirs up stuff we may have been carrying (sort of successfully) for a while and it can really tip our sense of balance. It’s not at all surprising but can be very disturbing and confusing. One thing at a time - focus on the good news of getting on with your next step of treatment, and how well you have been doing. But then have a think about how counselling might assist you in dealing with the stress you are still carrying. Many of us have found that a trained objective professional
ear (not a friend, not family) has proved valuable, sometimes very quickly. It’s no weakness just good medicine. Best wishes