This "hypersensitivity" and even paralytic fear must be understood as a narcissistic trait (people fail to recognize this, in part, because they have a limited view of what is narcissistic, as something necessarily bombastic, and of course, narcissism tends toward a blindness of one's own narcissism). By recognizing this to be the case, the subtle temptation toward self-pity, or normalization or even valorization of such qualities, can be prevented. Narcissistic traits are antisocial, and so it stands to reason that narcissistic traits impede one's ability to form healthy relationships.
> You are struggling against many aspects of the way we in the developed world/nerd world live.
The liberal consumerist hyperindividualism of our age is an anthropological position that conceives of human beings as atomized units that merely enter into transactional relations with other human beings. "Society" is merely something contractual and utilitarian, and in practice has the flavor of mutual exploitation. In effect, society is reduced to something like a marketplace. This is, of course, totally bogus and destructive. We are intrinsically social animals. Society is a common good, a superordinate good, toward which we have certain general, non-consensual moral obligations and something we need to flourish as human beings.
Because of the bad anthropology the contemporary world is rooted in, we often feel its practices and aims to be meaningless and hollow. We also find ourselves oscillating between the twin errors of collectivism and hyperindividualism. These two extremes are forced onto us by the paradigm of this false anthropology. One looming danger today is that, as the liberal order collapses, we do not know what will replace it. The loudest contenders are undesirable.
> more time-consuming relationship with our families than our parents ever did
That depends. On the one hand, family life was much more robust and lively in many ways than it is today. Parents weren't as careerist then in general. Families were larger, so the abundance of siblings meant you didn't have a lonely childhood at home, and a large pool of potential friends outside of it. Older siblings would assist with younger siblings, and children would participate in domestic duties, so in that sense, parents would not need to be as involved in all aspects of the daily life of the children and the functioning of the household. And in the past, families tended to concentrate more in the local area, so grandparents were typically near children and grandchildren and so on. In other words, a robust family life enables a robust society in general. Social life becomes "thicker" and mutually reinforcing.
The time-consuming element you have in mind is therefore related. All of the responsibility for taking care of aging parents falls on the few children they have or who live nearby. Without siblings or friends, parents step in socially more than they would with their children (or else consign them to the cesspool of social media and internet garbage). There are also cultural factors: parents can become overinvolved or inappropriately involved in some respects, like the proverbial helicopter parent, which itself can be spurred by the collapse of society around them, if not careerist ambitions for one's children.
Which brings us to your main point...
> You have to be the one who creates things to do.
Today, communities often need to be more intentional. If there isn't a community around you'd like to join, you have to be the one who initiates it. It's not guaranteed to function or last, but what's the alternative?
This doesn't "solve" the so-called loneliness epidemic, of course. The proposal here is more modest, namely, if you want people in your life, you have to look for them. Every community or social group needs a reason for its existence. The weakest form is rooted in utility, the second weakest in fun and pleasure. They are transient. The best and more robust kind are to be found in the common pursuit of virtue. In these and through these, we could begin to witness the birth of a healthy society.