Sometimes the problem is not you. Sometimes the task itself has quietly become difficult to move.
Tasks drift over time. They become vague. Bloated. Disconnected from why they mattered in the first place. Or so large that your brain no longer experiences them as a task at all, just an unpleasant cloud following you around.
Trying harder usually does not solve that. A badly defined task can absorb huge amounts of guilt while producing very little movement.
One thing worth asking is whether the task still makes proper sense in its current form. Not whether it matters in theory. Whether the actual version sitting in front of you right now makes sense to act on.
Sometimes progress begins not with discipline, but with redefining the thing properly.
Below are some articles that may help you understand this kind of stuck a little better.
There is a particular kind of task that follows you around for weeks. You think about it regularly. You keep meaning to deal with it properly. Occasionally you even sit down with the genuine intention of finally making progress on it. And somehow you leave the interaction feeling worse without the task having meaningfully moved…