Please not again....and not today please *sob*

why did depression come back to me. I was doing so good... Since Christmas ice been doing good....I cried and cut myself in the car today while listening to music. What's going on...and I have a feeling it's the same feeling and the same way 

*sob*

I don't know why...these thoughts come to haunt me but I don't get messed up by it. But now I have no reason and I'm all jacked up. I really need someone to talk to for once in depression.....