I can do the reports — why do messy calls still trip me up?

You know the mechanics. You can pull the numbers, build the file, format the slide. But when two sources disagree, or the story could be told two honest ways, you stall. Be plain with yourself: this is not an Excel problem. This is you avoiding a decision. Here is what you are not seeing. The messiness does not go away once you are more experienced. It is the job itself. There is no clean answer hiding underneath the conflicting numbers, waiting for you to find it with enough effort. There is only a choice, made by you, that you then have to defend. So stop waiting to feel ready. You get good at judgment calls the same way you got good at the reports — by making them, badly at first, and writing down why you made them. Nothing else trains this.