Hi @insomnibus
This is such a clear sight of your own mind.
There seems to be a divide for you, a splitting that perhaps served you well at one time in your life to protect you but that now needs to be brought together.
The clear eyed, good decison making living life is the one you want in charge of all of you. I understand the other part, the mean eyed sneaky hurt one, that watches and seems to sabotage and bugger things up and just waits for an opportunity when the clear-eyed in charge one is looking the other way to do something that ends up having bad consequences. I had such a split, and she caused all sorts of havoc (understanding 'she' was just part of me gone awry.
It is a wrestle with self, I saw this clearly in reading Ursula Le Guins The Wizard of Earthsea - where the character Ged finally faced his shadow, first fighting it, then embracing it, then brininging it inside with love and undertsanding. When I saw that laid out in this book I saw myself - and I worked hard to embrace my shadow.
It is all "me" just needed to be acknowledged (And thanked for trying to 'protect me' even though that part was pretty damaging, it is trying and failing to 'help' keep you safe from harm) and brought into love and held tight and not allowed to be the one to make decisions or act.
This split part needs somthing to do, give it a job. Put it in charge of solid things like balancing the budget, doign the shopping lists, planning to fix the shelves that have a broknen bracket. Take it along with you and keep it in check.
A different analogy.
If you have ever trained a dog maybe this analogy will help... The wilful, wayward puppy who didn;t get enough training grows up and always pulls on the lead, gets into trouble, rushes in where more sensible dogs wouldn't go. Needs to learn to heel, to look up to his owner and ask permission, to seek guidance, you want that dog to look up at you and ask "what should I do in this situation?", and wait for the command, "yes, say hello but no more". Or, "no, this doesn't look safe, let's keep walking."
So bottom line we need to be In Charge of the Wayward parts of ourselves (not so much "In control") we make the decisions and tell it what it can annd cannot do. it responds well to guidance and a firm, loving hand.
Hope all that makes sense?