Disconnected instead of detached

First Things First, samvega, is very base of the practise toward liberation, while foolish householder-equanimity and feeding on would lead one firm caught in the stream, good householder. Or does good householder, aside of his equanimity not still goes after pleasant signs, sound, smell, taste, touch, thoughts and with it still not living just on what is given?

As for being given of what one doesn't like, sees no refuge, there is all opening, as it wouldn't be required to make it yours. Disconnect makes only free after having followed the right connection, bound to the Gems, heading toward liberation, disconnected from worldly affairs and common ones. Wise to chose whether connected/disconnected with what is subject of, heading to, decay or not.

Meditation is blissful in its seclusion.

MN8:4.1: It’s possible that a certain mendicant, quite secluded from sensual pleasures, secluded from unskillful qualities, might enter and remain in the first absorption, which has the rapture and bliss born of seclusion, while placing the mind and keeping it connected.

Yet that blissful freedom from everyday concerns creates a challenge.

MN8:4.2: They might think
MN8:4.3: they’re practicing self-effacement.
MN8:4.4: But in the training of the Noble One these are not called ‘self-effacement’;

It creates a challenge as soon as we re-enter the everyday world with its demands and concerns that require some connection.

To address the dangers of disconnection, the Buddha teaches ethics as a guide to making positive connections.

For example, if a good friend comes to us in pain, we might delay our meditation a bit and talk to them kindly to avoid being cruel.

MN8:12.2: ‘Others will be cruel, but here we will not be cruel.’

And if we meditate best on a favorite cushion but another is struggling in pain, we might share that favorite cushion and use another cushion that serves almost as well for ourselves.

MN8:12.30: ‘Others will be stingy, but here we will be without stinginess.’

Ethics protect us against harmful disconnection.

DN34:2.3.4: First, a mendicant is ethical, restrained in the monastic code, conducting themselves well and seeking alms in suitable places. Seeing danger in the slightest fault, they keep the rules they’ve undertaken.
DN34:2.3.6: This is a quality that serves as protector.

I have a slightly similar problem: which is that if someone else is unhappy or worried about something then I find it hard to empathise (i.e. I too am "disconnected").

When they tell me what they're worried about (e.g. someone's friend dying in hospital), it's like I have developed an "immune reaction" to that kind of sadness, and think to myself, "Well of course that kind of thing, illness, that is only to be expected eventually", maybe other thoughts like, "I'm happy to remember that friend because I remember them as a good person" -- but it's difficult to explain my reaction to the person who says they're suffering (i.e. to share it with them).

Still, perhaps that suggests one type of antidote to the problem -- i.e. more empathy (and possibly finding more occasion for empathy). If you study the Brahmaviharas (and there is much of that subject on Access to Insight), it says that "Pity" and "Indifference" are two of the "near enemies".

I think that part of the root of these (e.g. of "Pity") is "conceit" and especially the act of "comparison" (e.g. "you are upset and I am not") -- How are 'conceit' and 'identity-view' not the same?

Secondly, another antidote might be "virtue" and "virtuous behaviour" in general. The "river" shows up as a Buddhist metaphor as being something to be safely crossed or even escaped from, instead of being carried along and swept away by it. You say with less meditation you are more like a navigable boat and less just floating. I'm not sure I can advise you on that, perhaps it's why some people become monks, i.e. to practice meditation instead of other goals.

Thirdly it might help to consider also (maybe to take pleasure or ease in) what doesn't exist and use that as some kind of motive (instead of only being detached from what does exist) -- I found this answer helpful.

Disconnection is a kind of aversion; it's the egoic self protecting itself through avoidance. Detachment doesn't deny, diminish, or avoid the experience. If mental phenomena are arising they are exactly what's happening at that moment, and we shouldn't dismiss them as meaningless or valueless. Mental phenomena are the mind and body trying to make us aware of something. Acknowledge that and take it seriously, but keep firm in the attitude that we are not dealing with that right now. We want to teach the egoic mind to have some discrimination, so that it only intrudes when it's useful and necessary.

I mean, consider... If we're sitting in meditation and we experience certain arisings — a smell of wood-smoke, a deep crackling sound, a flickering sensation of heat and light at our back — we probably want to get up off the cushion and go call the fire department. We could sit and observe the phenomena until it dissipated, which it eventually would, but that might not bode well for our physical form, or for others in the building. Any arising we experience is a signal of that sort, though more often than not it's merely a signal that our thinking mind is fretful and bored. It's important to engage the signal with attention, but not to act on it or give it power unless it's actually a pressing concern. Meditation time is not the time for that, and whatever it is can come back when we're done.

We don't want to sit and experience the river like a piece of driftwood headed out to sea, any more than we want to kick and flail about like a drowning man trying to save himself. We watch the river like a pilot setting a course, unconcerned but actively aware, finding that middle path where the waters are deep and the currents are favorable.

I'm not an expert, but from what I've read and experienced, while the connection to one's own (afflictive, egoistic or trivial) emotions decreases, love, compassion and a general connection to others can increase. To cultivate this, you could practice meditation on the four immeasurables (loving kindness, compassion, empathetic joy and equanimity, e.g. with sessions from this retreat: https://media.sbinstitute.com/courses/spring2012/). Maybe - I don't know you or details of your experience - it would also be helpful to talk to a psychologist.

As Rome burned, Emperor Nero stood disconnected and detached. He blamed the Christians for the fire. Disconnection and detachment are attributes of the dimension of nothingness.

Although we might attempt to escape suffering in a shell of nothingness, it is a hollow shell separated from others. And we might escape further into neither perception or non-perception, yet find there no lasting relief.

Ultimately we might be left alone with hunger and food, cold and shelter, loneliness and a caring friend.

MN121:10.4: ‘Here there is no stress due to the perception of the dimension of nothingness or the perception of the dimension of neither perception nor non-perception. MN121:10.5: There is only this modicum of stress, namely that associated with the six sense fields dependent on this body and conditioned by life.’

And with those common needs remaining we might realize the futility of running away. And we might turn around and practice our lives for one and all.

AN4.95:3.3: But the person who practices to benefit both themselves and others is the foremost, best, chief, highest, and finest of the four.

And that is why right ethics is the foundation of all right practice.