How long is someone allowed to exist like this?

Living with mental illness: permanence, waiting, denial

January, from my diary:

January 16 2023. I want it so badly - the feeling, the relief and settling in. But I am also scared that whenever I think it will finally happen, it doesn’t, and I realize the feeling I’ve been waiting for doesn’t exist. I am scared of that because it makes me wonder if I will always be unhappy and isolated and underperforming. I can’t fathom an entire life like that.

January 18 2023. I am so empty and depressed. Every random moment I find myself in my head saying “I hate my life” or “I hate myself”. Those are literally my default filler thoughts. How long can someone exist like this?

January 22 2023. I am so depressed. I don’t want to do anything. The feeling is so overwhelming. I don’t want to be 23 and still like this, still here. I am so unhappy it’s like a mist that’s seeping around the space in my brain and filling every spare moment.