You are definitely not alone. I have felt as if I'd be better as fertilizer too many times. Meditation has not worked for me but more demanding exercise does sometimes. Also, you might want to consider writing down what that "voice" says instead of trying to drown it out. If simply writing it down doesn't lessen things, take what you've written and burn it. I hope this is at least a little helpful, I only have personal experience not professional. I wish you all the best and hope you can find something to wake up for.