If you have a migraine or a broken leg, you suffer and then it gets better. If you have a terminal disease you either recover or you die.
If you're slashing at your wrists, having hallucinations and delusional whilst crying 24/7, you're depressed enough to warrant being depressed. The depression is visible and thus real. If you have situation or event triggered depression, people will molly coddle you for a while then it's a 'there, there dear. You'll be okay soon' which translates roughly as 'Oh gosh, how terrible! I don't know how you cope.' which then turns to a 'pull your socks up' after they deem you've had long enough to 'get over it'.
Yet, If you suffer from long term depression, anxiety or personality disorders that was triggered by nothing other than faulty wiring or genes, people rarely know what to do. They understand neither the longevity nor the peak and troughs that accompany it. You're not seen as ill, you're just flaky and mercurial. You obviously can't have Social Anxiety because they saw you say hello to someone last week. You're obviously not depressed because a few days ago they saw you smile and Egads, laugh. You, you faker you!
The thing with invisible illness' is, people only accept them in their most visible moments. They only see the mask.
Mental illness isn't just about the darkness, It's the torturous rays of light that momentarily blind and panic you too. It isn't just about the blackness, it's the fifty shades of choking grey in-between. It's not just the drowning, it's the unexpected hard slaps that put you off balance.
It's not that you're okay or even not okay, it's the varied struggle of trying to be okay. It's the soul cracking realisation that you may never be okay enough, again.
& the mask keeps slipping.