Disclaimer: this is how I personally experience depression.
Everyone who struggles with the same mental illness may not experience it the same way I do, so please do not assume this is the same for everyone.
Sometimes you wake up, and you’re body won’t move. It doesn’t matter how much you try wiggling your toes, going through the motions of getting up in your mind million times - your body just refuses to move. And that’s okay and valid. And even though you’re trying really, really hard, it doesn’t seem like the body will respond to you, so you just lay there for hours trying to do something that feels so utterly impossible.
Sometimes you wake up, and a whole plane of anxiety just smacks you in the face. Every single little thing is another small scratch on your body, keeping you awake and aware and terrified. And even if you wanted to go to sleep, to leave these problems for later, the individual urgency of each little deadline creeps on you, wraps its claws around your mind like a constant shouting in your ear of you’re going to be late, be late, late, late, late.
It is so loud that you can’t fall back asleep, although the crushing responsibility you feel means that you can’t actually start on any of it either. Instead, you are drifting away from your body, seeing things in the third perspective, consciously watching as the hour's pass, your deadlines get closer, and your body becomes mushier with the feeling of having done nothing.
Sometimes you wake up, and you’re floating above your bed. You’re tired and wide awake and aware and incoherent and you can only hear a faint moaning of someone struggling to move. But it takes you maybe 30 seconds to realize that moaning is you but you see the entire body from a bird’s eye view so that body can’t be you, and the lifelessness of the body feels so entirely different from the blankness of your mind that it couldn’t be the same person. But as you try to ground yourself a little bit more, you feel yourself both sink back into that body and break away from it more.
Sometimes you wake up, and you feel all three of the previous paragraphs intensely intertwined to the point where you cannot separate where the depression begins, the anxiety ends, and the dissociation is mixed in. You feel like you have been run over with all these feelings and you’re feeling all of it too much and not enough and there’s this frantic yet lethargic worry that you’re not going to get anything done today. And sometimes, you’ll achieve the small victory of making it down to eat breakfast or lunch or dinner. But at the same time, these places are too loud and smelly and filled with too many people and the taste of your tongue in your mouth is a little too much and the feeling of your clothing is likewise overwhelming. And sometimes everything is too little and too much and you can’t process anything that’s happening.
So, if anyone ever tells you they are having a bad day, mental health wise, please consider how much strength it could have taken them to get up in the morning, how much strength it could have taken them to continue the day. Understand that, and just let them do what they need to do to make it through the day instead of harassing them about how they look fine or how they just need to stop being lazy or any other form of invalidation.
Don’t make it a big deal, just let them know they are valid and you admire their strength and anything they are feeling is okay. Because to those of us with mental illnesses, it’s a struggle we deal with our entire lives, not some big tragedy or anything we wish would have attention drawn to it.