For me, constant fantasising about suicide & how I'll do it, feeling numb, no interest in anything, always one step away from tears - as in, you can feel them behind your eyes, all day every day.
The first thing you do when you wake up every morning is burst into tears that you're still here.
Not caring about anything. Struggling to force a smile and I do mean struggling.
I hate slang terms but one I do relate to is being "in a dark place" it's just so accurate. That feeling of helplessness. You genuinely believe there's no way forward whatsoever. Like you're underwater, but fully believing, knowing that you'll never, ever reach the surface no matter what you do or how hard you try.
Most of all though, it's an overwhelming (and I mean that literally) feeling of loneliness. Even when you're not alone.
Feeling unable to get out of bed, unable to interact with anyone. A self hatred so deep that hearing your own voice or even just your own inner monologue, sickens you. A self hatred that makes you truly, truly, wholeheartedly believe that every single person you know DESPISES^^ you, even your closest family & your friends.