The doubt sits under the competence
Mercury in Capricorn points its questions at the 12th house, so the assessing, demanding, structural part of your mind is turned inward and kept there. Outwardly you are capable and unbothered. Internally there is a standing evaluation of whether you are actually adequate.
Nobody has seen the evaluation and it has never had to survive contact with anybody else's opinion. That is why it has held its position so comfortably for so long.
A private ledger of things that fell short
You keep an accurate internal record of what you did not manage, did not finish or did not do well, and it is considerably more detailed than the record of what worked. Both lists exist and only one gets consulted. Write the other one down with the same rigour. Applied evenly, your own standard produces a substantially different verdict than the one currently running.
The standard operates with no audience
You assume the demanding voice belongs to some external judge, and in this position there is not one: nobody is watching, nobody set the bar, and the whole apparatus is self-hosted. That is worth establishing as a fact rather than a reassurance. A requirement with no author can be renegotiated, and you have been treating it as though it came from somewhere with authority.
Rest has to be put in the calendar
Stopping is not something you will ever decide to do in the moment, because there is always a reason not to and the reason is always sound. Book it as an appointment with a start and an end. Treated as an obligation it happens; treated as permission you are granting yourself, it has never once happened and will not begin now.
The composure is doing a great deal
You can be some distance into a difficult period with no visible change in output, manner or reliability, which means nothing in your environment will prompt anybody to ask. That is not strength; it is a communication failure with a respectable appearance. Tell one person that a situation exists, without detail if you prefer. The existence is the part that matters.
The voice belongs to somebody specific
The internal assessor speaks in a particular register and it was learned somewhere, usually from one person in your household who set the terms of approval early. Identify who. That single act changes what you can do with it far more than any amount of arguing back does, because a requirement with a name attached is a person's opinion rather than the structure of reality.
The tiredness has been there for years
You have operated at a low baseline for long enough that it now registers as normal, and you would only detect the difference if something removed it for a while. That is worth testing rather than assuming. Take a genuine fortnight with nothing in it and pay attention to what changes during the second week, because the first week tells you nothing at all except that you are bad at stopping.
Nobody is going to hand down the verdict
You have been working toward an approval that would settle the question, and there is no authority in this arrangement empowered to issue one. It has to be self-declared or it does not arrive. Write down what would constitute enough, sign it yourself, and treat it as binding. That is a strange exercise and it is the only mechanism available here.
You will not let them see you struggling
A partner gets the competent version through the worst of it, because being carried feels like a failure of the arrangement rather than part of it. They generally want to help and have never been given anything to do. Say one true sentence about a hard week. It is not a burden you are placing on them; it is the thing they signed up for.