Depression?

So I've been feeling really feeling sad lately. I wanna cry all the time and self harm. sometimes I feel like it's hard to eat and I just don't wanna do anything anymore and I always feel alone and worthless. Am I the only one that feels this way please tell me I'm not alone I've had problems with depression in the past and I've always been able to get threw it but it seems like it's so hard to control and I'm terrified. It takes all my will power not to hurt myself.