Whats wrong with me?

I've been having really bad mood swings lately. One minute I'm absoultey hypo, loving everyone next minute I'm sobbing hysterically. And all the times in between I feel like cr*p. Alot's been going on in my life at the moment but normally I can cope really well. My Nan's terminally ill, and suffers from dementia and I can't even stand being near her. I feel so horrible, we don't have much time left and I feel like I'm choking if I'm in a room with her for more than 15 min. My best mate betrayed me then moved away, I really love him though and it hurts so bad. I can't even talk to him, the silence is horrible. My brother moved to, he was my best friend and confidante but everytime I talk to him now we end up in a fight. I lost my job and have had no luck getting a new one and money is dwindling so fast. I feel I've hit rock bottom and can see no way out. Most nights I cry myself to sleep for no reason and when I do sleep I end up screaming out alowed. The smallest thing sets me off in a fit of hysterics or a fit of tears, it's like I have no control over my emotions anymore. I even get really angry too especially at my youngest brother and the poor kid never does anything wrong. Whats happening to me??
I'm so sorry for the long post, I'm just so confused with myself. What do I do?

You're growing up.
I'm going through the same thing.
Not nice is it =(
But it gets better.

There is nothing wrong with you!
You've said yourself that you are going through a rough time.
Try maybe channeling your frustration to a focus. For some, writing works, for others maybe a pair of boxing gloves and a punching bag and yet others just need someone who will listen.

It's called puberty :)

You're perfect, nothing's wrong with you. Life just gets difficult sometimes. :-*