I can run stock fine—why do shrink and counts still rattle me?

You handle the daily work without trouble. Receiving, stocking, rotation — none of that shakes you. It is the count, and the shrink line on the report, that gets under your skin. That tells you something: this isn't a skill gap. It's a confusion about what belongs to you. A shrink number is made of many hands, many days, many causes — some yours, most not. If you treat the whole figure as your personal failing, you will dread every count whether you did anything wrong or not. That dread will not make you more careful. It will make you anxious, and anxiety is not the same as diligence. The fix is not to care less. It is to care about the right, smaller thing: what did you actually do or fail to do between one count and the next. That is yours to examine, yours to correct, and yours to improve. The rest was never in your hands, so stop carrying it like it was.