How do I handle work that demands more precision than I can manage?

The weight you feel is the weight of caring about doing it right. Precision work is unforgiving, and standing in front of it can feel like standing in front of something too big for your hands. That fear is not a sign you cannot do it. It is a sign you understand how much it asks. No one holds tight precision by trying to be perfect all at once. They break the work into small steps, each one checked before moving on. The overwhelm comes from looking at the whole finished thing and its tolerances all at the same time. Look instead at the single cut in front of you, and only that. Tomorrow, take one job and work it one step at a time, measuring after each. Do not think about the finished part. Think about this cut, then the next. Precision is not a leap. It is a hundred small careful moves, and you can make one careful move. Then another.