Why does planning my career feel like too much to handle?

Here is what you are actually doing: you sit down to plan your career, and instead of one task, you load ten years of decisions into your head at the same time. Then you call that weight "complexity" and feel crushed by it. But the weight is not in the task. It is in how you are carrying it. No person plans a whole career in one sitting. Not one. What you can do is choose the next right action — one conversation, one application, one hour of honest thought — and do that. The rest does not need you yet. You already know this when you are calm. The trouble is you keep testing yourself against the whole mountain instead of the next step on the path. Stop testing yourself against the mountain.