Strugglin

I am stugglin to keep my head above water right now. I feel like I'm fighting a losing battle. I'm being drug under and can't stop it.
I have been fighting some depression, again. I don't know how to shake this. I hate feeling like this. I feel worthless. I hate myself and my life. I hate feeling like that even more. This totally sucks.
This isnt the first time I've felt this way either. I have little spells of this off and on. Usually its a matter of a vitamin deficiency, but I'm on a multivitamin now and thats been working for a while. But my body has a way of getting use to things and I think thats what where I've hit again.
Why can't I just be happy? Why can't I just be a happy person? I hate this!
I don't know how to fix it or make it better either. I wish I did.
I wish I had help!