Kingdom of Knuffel

I'm absolutely frustrated and stressed out. I think I'm making a huge mistake in my life, but I can't stop. What am I doing? Why am I doing it? Should I try to change it or will I just end up in a situation that's even worse?
I don't have any motivation left - I can't see the point in doing anything. Even when I try, when I feel I've done okay, I find out I failed once again. So I close the doors and draw the blinds and cry while nobody can hear me. I don't want them to see me cry, but at the same time I feel so alone.
I put on a happy face in front of everyone and act like I don't care or like I'm fine when I'm in fact struggling just to look natural. It's okay, nobody notices since I'm not close with anyone anyway. But sometimes I wish they would ask: 'Hey, are you sure you're alright?' I push them away myself, I know. That's just how I am - a failure of a person. I know I'll die alone and unwanted.
I just can't stand it... I don't know why I'm doing this. I just clench my teeth and try to get through another day. But it's getting harder. I know there are people who have greater problems, but I'm not other people. What's unimportant to them is important to me.
I wouldn't go as far as trying to kill myself, but when nobody's around I often say to some invisible force that perhaps might be listening: 'Please... Please, just kill me...'

Just please shut up and accept the fact that I can't cope like a normal person.