What happens is you have this amazing energy, everything's funny, everything's beautiful, everything's amazing. You can't remember ever not feeling this way, you've always been there, everyone loves to be around you - until something doesn't go your way, and then it can (and will) get ugly. You see a side of yourself that you know didn't come from you. This both frightens and empowers you.
And then eventually, and this always happens, you crash. You crash faster than the time before, and you can't get out of bed for days. You're functional, mostly, but it takes effort and you're sure it isn't worth it. You do it to keep them all quiet and happy, when you can manage it, but really, you'd rather never leave your secret space, wherever it is.
You know what to do - just to ride it out, because just like you always crash, you always get better too. Except you can't see why you should bother riding it out, because it's only a matter of time before you're right back where you started.
You're tired of yourself, and you know that no matter how much all the people who love you care, they're tired of you too. You physically hurt yourself in various ways and you can't feel it at all; this frustrates you.
And the dreams - the dreams are something else. You feel like you're dead in the day and come awake at night, when you dream, and it's amazing and scary in an inception-esque sort of way. A dream within a dream, within a dream. Things start to happen in real life which you forget because your mind thinks it was a dream, things happen in dreams and you think they are real. People think you're being silly or making stuff up, but you really aren't. Your dreams are lucid and this doesn't make anything easier. You have conversations, in your dreams, between your real self and your dream self. And when you wake up, you can't remember who said what, what's real and what isn't.
All you know is that today, whether you're okay or you're not,
this too shall pass.
And that's both comforting and terrifying at the same time.