Depression?

I can't say that i feel like myself anymore. I haven't felt like the same person in years. I always feel sad. afraid. worried. stressed. I remember the good old days and how carefree and happy i used to be. I haven't felt truly happy in such a long time. I feel empty. I'm always afraid that something bad will happen. I'm constantly stressing about everything. I feel like things will never get better. I feel so alone. Like I don't have any true friends. I've become such a negative person. Always expecting the worst. Just not myself.