Why do I feel like I have to hold everyone up?

You are good at seeing how things hold together — a plan, a team, a project, a person. Because you see it clearly, people lean on you. Slowly you stop noticing where their weight ends and yours begins. This is not humility. It is a quiet kind of pride — the belief that if you don't hold it, it falls. Test that belief. Most of what you carry was never yours to carry. You picked it up because you could, not because you must. A beam does not choose its load. You do. That is the whole difference between you and the structures you analyze.