Loneliness is blunt, clear, recognisable.
It is when you're either within or outside the circle, but never part of it, no part of you can ever touch the circle. You can't be like the others, and people do not accept that which they do not recognise. Very probably you don't really like the others just as much as they don't like you, or simply there's nothing in common or you're too shy or whatever. But the point is, that at no point does the circle touch you. You find yourself alone.
ALONE. It makes you feel worthless. It makes you sit on your bed listening to the saddest songs you know and cry to yourself asking it why it is so unlovable. What is wrong with you? You look for answers anywhere you can find them, asking what's wrong with you. Why are you so, so, so terribly unwanted, when all you want is to get along and it all be rainbows and butterflies and you try to be nice in your own shy and awkward ways. But why can't you be out there with everyone else. What's so bad about you that you're condemned to this lonesome life, sitting inside in your messy room.
You hate the mess, and the unwashed dishes, but not even your OCD can get you going. You're not depressed. You're lonely. There's no one there when you win, no one there when you loose. No one to climb towards and no one to fall back to. No one, just you. You might as well eat something nice and sleep and do this everyday on and on again. Suicide is not an option either. You feel so bad and so ashamed about yourself that you won't do anything as controversial as that. You know you won't be able to truly go through with it. You know that all you hope to get out of it is people to notice you and you're knowledgeable enough by now (boi you've tried it) that it doesn't work. You can only sit there, hope something will change or the pain will stop. You just want the pain to stop...