Your post is insightful and full of feeling. I identify with a lot of what you've written. But similar to what
@Outdated wrote, I don't see it as entirely negative. So far nothing I've learnt about the world gives me reason to think that there is some externally created purpose to our lives, or some story created by others and we have a role to play in it. So a sense of not belonging anywhere seems normal to me. It doesn't have to originate in self-loathing. It's just a consequence of the universe's indifference.
@Neonatal RRT wrote "At some point we need to stop thinking about how others perceive us" and I think that's the best way I've found to accept the universe's indifference and still get up each day to do things. The acceptance that I don't matter and the dissatisfaction that comes with that realisation, is inseparable from liberation, by which I mean the freedom that comes with knowing that I define my own purpose in this life.
I decide what is right and wrong, what is worthwhile and what isn't. This does not inevitably lead to selfishness. This understanding often leads people away from apathy and motivates them to do things differently - and with more meaning, compassion, and impact.
About 10 years ago I hit an all time low. I considered ending my life and was finding it so difficult to get out of bed and eat. So I quit my job and left my home and lived rough for some time and ended up in a different country, spending all my time volunteering with a couple of charities. I met loads of new people and quite often they'd ask how I ended up where I did, or they'd ask why I was doing what I was doing, and I used to say that I can't think about that - I can only think about what is in front of me. Everything else is too big. If someone is right here and needs help, I'll help them. The moment I think about the world beyond, I get depressed - precisely because there is no reason or purpose to it and there is so much suffering and I can't fix it all. But if I define the parameters, that enables me to define a purpose. This person is hungry, I'll try to feed them. If I think about the bigger picture I know that feeding them ultimately means nothing. But at this point in space and time, food would make the hunger go away and that means my actions can make a difference.
The problem I have is that in everyday life there is a constant puncturing of that bubble. I can't just focus on what's in front of me because society makes constant demands. And in fact I make demands of myself, because for example I have attachments to people in my life and I want to do things for them and with them.
The only time in my life I've felt comfortable is when I ran away, wandered aimlessly, and just focused on what was in front of me. For a while I was able to hide from society's demands and focus on individual needs, and it felt both pointless and liberating.
