Hi, I've looked around for answers but they all seen to be on babies or puppies or something stupid like that, so, I'm not good at this type if thing so , here goes.

I'm a 13 year old girl and for most of the day I seem to be fine but when it comes to night and I'm in bed I just burst out into tears and hate myself for it. I have a good life and all but recently I've been down, tired and yeah. And when I do get to sleep I wake up and can't get back to sleep for a long time after.
Anyone know what it is? Any answer will be appresiated.