I don't know if it helps, but here is the mindset I've adopted since about my first follow-up scan.
Your primary tumor is gone. If the cancer spread, then it already spread, and it will show itself eventually. There is really nothing you can do now except be vigilant, keep yourself healthy, and live your life between scans with a little more urgency than the average person. Every time you get a clean scan, it is like your time of being healthy (not on chemo, not talking to doctors) is extended by 6 months. This is a huge gift. Use the time so you don't have any regrets.
Second, even if you do have a recurrence, it is, prognosis-wise, not the same as being diagnosed at stage 4. If/when a met shows itself, you will catch it early and the surgeons will be ready for you. When my lung met was found, it was almost a relief. It had been hiding there since some years before my diagnosis. Once it showed itself, they could get to work cutting it out.