To be honest from reading both your posts I think you're someone on the cusp of sorting all this out.
You seem very self aware and taking actions to improve things, even if you haven't been able to target it quite in the right place yet. I see myself in you, I used to (still sometimes do) found myself despairing at the actions of others at work or in life in general even though I didn't feel I'd done anything to them. There needs to be an acceptance that you can only really do you, you can't control others. And as you say, they're probably just as messed up!
Don't be drawn towards 'friends' you know are arseholes just because you've felt loneliness etc. I've made that mistake, I hated myself so I forced myself to go to football etc with people who were a negative influence. I was a figure of ridicule when I was a fat f**k, not that I mind having the piss taken out of me, but no one ever realised that I got fat because I'd given up on myself and just stopped looking after myself, they just wanted their laughs.
Get comfortable spending time alone, build your self confidence and self motivation then start meeting people. Then you'll be confident enough to know who is worth your time and who isn't. That sounds a bit isolationist but I left all the whatsapp groups I was in, stopped going to big group events and immediately noticed the absence of the constant negativity. And you know what? The mates who gave a shit about me I ended up seeing and speaking to regularly anyway, whilst the dickheads disappeared.
Sorry that possibly wasn't very coherent but happy to talk in more detail if you like. Also have you read Goggins book/listened to audiobook, well worth partaking in if you've only done youtube videos etc up to now.