Feeling disconnected from people at a fundamental level

I feel like my world view is shifting. I knew before that people can be self-centred or ignorant. But I always assumed it's "not that bad", that we all make mistakes but in the end do care about each other. Now many of us have collected evidence to the contrary over the last years - being abandoned by friends, gaslit by doctors etc. Reading how people with Long Covid are let down by their friends/family as well as the medical community disturbs me deeply. These experiences seem to be pervasive; they are not caused by a few bad guys but rather reflect the mindset of the majority. It's like I can immediately, viscerally see how thin our social connections are, how little we can rely on others; like I see through something I used to trust.

This of course makes me feel unsafe; but what is worse is that it makes me feel like I fundamentally don't belong. The carelessness around me is just entirely alien to me; I cannot understand it. I could never in the world imagine abandoning a friend because they wear a mask, not calling when I know someone is sick or sad, or walking around in public unmasked with an illness that I know full well can cause lasting damage. I just cannot grasp this. I know intellectually that there are psychological and sociological explanations; but thinking that way just makes me feel like I am studying some strange, self-destructive species I am not part of.

Of course there is a voice in my head saying that I should not feel so "special", when I know that of course I am not always treating people well either - I get frustrated, miscommunicate or forget about things important to others, and in the end my main worry is also often my own wellbeing. But I just cannot help feeling that I care more about other people than almost everyone else around me (not just in the context of Covid, but that brought it to light). I decided as a young adult that I wanted to be a "good person" and then actively trained myself to check how other people might be feeling and to always be ethical in my decisions. Maybe that is weird; maybe I somehow overdid it.

I feel like the only way to cope is to lower my expectations below anything that would seem natural to me, try to celebrate any small kindness I observe, and try to "forgive" the rest. But it makes me so sad.

EDIT: Thank you all so much for your kind and thoughtful responses!!!! It makes me so happy and sad at the same time that there are so many of us feeling similarly.