You know exactly what you need to do. You have known for three days. You even want it done. And still you cannot make yourself start, and the not-starting is somehow more exhausting than the task ever would have been. If that is familiar, you are not lazy and you are not broken. You are running into activation energy.
Starting is a separate skill from doing
For an ADHD brain, the effort to begin a task is not proportional to the task. A two-minute email and a two-hour project can feel equally impossible to open, because the barrier is not the work, it is the transition into it. The brain is waiting for a hit of interest, urgency, novelty, or pressure, and a plain to-do gives it none of those.
This is why "just do it" advice bounces off. It treats starting as a willpower problem when it is really a state-change problem. You are not failing to push hard enough. You are missing the on-ramp.
What actually lowers the barrier
A few things help more than trying harder. Shrink the first step until it is almost too small to refuse, so the task becomes "open the doc" rather than "write the report." Make the next physical action obvious so future-you does not have to re-decide what to do. Borrow urgency and company by doing it alongside someone, even silently, so the transition has some social pull. And get the task out of your head entirely, because half the paralysis is the low hum of holding it.
The point is to stop relying on a burst of motivation that may never come, and instead make starting so small and so obvious that there is almost nothing to resist.
ADHD Notes is built around this: it captures the task with a clear first step, breaks the scary ones down, and lets you start a focus session so you are not beginning alone. See how it works.