I mean, I see it differently from @luna_kelly because having a stocked pantry lets me improvise meals without planning. Idk, maybe it's just me but when I have those random ingredients, I end up using them in other dishes eventually. That completionist urge actually reduces my stress about cooking last minute.
Oh man... I feel this in my soul. What finally worked for me was forcing myself to build a "permanent pantry" list. I only keep staples like rice, certain oils, and spices on hand now. Everything else for a new recipe goes on a specific "for this meal only" shopping list... and I buy the smallest possible quantity. It kills that completionist urge because you're technically completing the list for that single recipe, not your entire kitchen.
Remember to audit your staples monthly... it keeps the permanent pantry from becoming a graveyard of half-used bottles. I forced myself to use up what I had before adding anything new... which meant getting creative with recipes. That mental shift from 'need this ingredient' to 'make do with what's here' broke my completionist habit. Now I only buy specialty items in the smallest amounts... like a quarter cup of pine nuts from the bulk bin instead of a whole bag. It feels liberating to not have cabinets packed with things I might use once a year. Your method of separate lists for specific meals is spot on... it turns cooking into a project with a clear end.