A lot of leftists spend a lot of time on pure critique of the system, especially early in their radicalisation, which can lead to a pessimistic outlook. It's true that the system is unrelenting and the effects of capitalism and domination seep into every aspect of our lives, and that can feel overwhelming. I really hope I haven't sabotaged myself by assuming that everything around me is cynical and only trying to exploit me at every turn, because that just isn't true. The system works that way, but there are lots of people living under it who don't collaborate with its goals.

Also, a message that doesn't get emphasised enough is hope. That's because algorithm-driven social media - even the fediverse is subject to this - tends to push ragebait and hit pieces over constructive narratives.

I'm really enjoying a lot of Anark's stuff lately on youtube. I'd really recommend his work on Hope and Constructing the Revolution.

Also I would recommend thinking about how you can join the anarchist practice of prefiguration, or building the new in the shell of the old. A lot of revolution talk focusses on toppling the enemy system, but equally important is building our own alternatives that make people's lives better now. That alleviates problems now, it wins people over and helps radicalise them, and it necessarily involves building community, which can hugely help with the feelings of isolation and depression.

I've often wondered if the horrific anxiety people experience in our society is our ancient monkey brains trying to figure out what we did wrong that isolated us from our tribe, when the thing that did it is communities being atomised by capitalist property markets. That observation on its own has helped me reach out more, and also to better accept when I don't have people around me.

Edit: I read this as the OP's question and I answered it as such. That's okay though, if this question relates to you, then you already know who you are.