There is a person you turned into family
There is somebody you decided was family, and once that decision was made the relationship stopped being something you could evaluate. Pluto in Cancer in the 7th house puts survival-level attachment into one-to-one bonds, so your partnerships are held at a depth most people reserve for blood.
Pluto crosses a sign slowly, so the Cancer setting is the shared half here, common to a very large group born across those years. The 7th house came from your birth time and is the individual half. It puts the attachment onto the person opposite rather than onto your household, which is why leaving anybody has always felt closer to abandonment than to a decision.
The test is seeing them accurately
The recurring situation is a partner behaving in a way you would not tolerate from anybody else, and the family designation makes it invisible. You are not making excuses; you genuinely cannot see it. Ask somebody outside what they observe, once a year, and take the answer seriously rather than defending against it.
Attention that is partly a scan
Partners experience you as extraordinarily attentive, which is accurate, and a good part of that attention is a permanent scan for what might be about to go wrong. The care can be given freely and costs you nothing. The scanning costs you the enjoyment of the person and it runs whether or not anything is happening. Learn to tell the two apart while they are occurring, because from inside they feel like a single act.
The fear is of being left, not of conflict
On being left. Not on conflict, not on disagreement, not on being criticised: on the plain possibility of somebody going. That fear makes a great many of your relationship decisions for you, including several that look like generosity from outside. Name it out loud to whoever is closest, in those words. Unnamed, it will go on arranging your behaviour without ever asking your permission.
Closeness that does not require merging
What you want is genuine and the form it takes tends to be total: shared everything, no separate territory, two people operating as one unit. The version that lasts keeps both people distinguishable, with separate friendships, separate rooms and opinions held out loud. Add one of those deliberately this year. It will feel like introducing distance, and it is the thing that makes the closeness survivable over decades.
You cannot assess somebody you have adopted
Once a person is inside, your judgement about them switches off, which is why you have stayed in situations everybody around you could see clearly. That is not naivety, it is a category error you make with people you love. Ask a trusted outsider one direct question a year, and let their answer count as evidence.
One friend at a time, all the way in
Your friendships are few and intense, and each one occupies the position of the close person for a stretch of years. When one ends, the gap is enormous. Keep two live rather than one, not as insurance but because the whole weight resting on a single person is a great deal to ask of them.
You became yourself alongside somebody
Your development has happened inside relationships rather than alone, and every significant turn in your life has another person standing in it. That is a legitimate way to live and it is not a lesser one. It has also left you with almost no practice at deciding anything by yourself. Make one substantial decision this year without consulting anybody, not because consulting is wrong, but because you have never found out what your own judgement sounds like unaccompanied.
Your output depends on who you answer to
The relationship with whoever manages you affects your work far more than the work itself does, and a bad one flattens you in a way that difficult tasks never would. That is not fragility, it is how your attention is wired. Treat it as a hiring criterion rather than a weakness to be overcome. Interview the person rather than the role next time, and take your reaction to them as real information.
Your partner and your relatives, in one system
You do not keep the person you are with separate from your family, and any friction between them lands on you as a genuine emergency. Some separation would help everybody. Let one disagreement between them run without mediating it, and find out that it does not have to be your problem to solve.