About your last paragraph. It has always puzzled and bothered me that there is this popular notion that to truly understand the world is to be miserable and hopeless - that there exists this trade-off between knowledge and happiness.
For me, the one blinding truth that exists about humanity is its undeniable progress on the grand timescale. You won't find anyone arguing really that we are worse off now than we were 100 years ago. I'm talking about the extremely basic progress indicator of the average quality of life of a human being on Earth (which is of course mostly subjective). Expand the timescale back beyond 100 years, and our progress just becomes more and more clear. We are so much better than we were 500 years ago in every single aspect of living on this planet: health care, wealth distribution, civil rights, freedom, scientific discovery, overall happiness... There is not a single aspect of humanity that was better back then.
I should note that a huge reason our progress is not always as evident within 100 years is this pattern of people's adamant belief that the generation below them is somehow screwing up the world forever. Technology is making people stupid/socially retarded, music these days sucks, no one cares about other people anymore, blah blah blah. I could talk for hours about how much I hate this, but I'll just say that it is incorrect, and aspects of that idea that are true stem from the fact that younger people are generally stupider than older people, because they haven't lived as much. Everyone was once stupid, and "Kids these days" will eventually learn, like everyone does.
If you let yourself become affected by the misery and despair that is definitely still around us on Earth, then in my opinion you are a part of the problem. You may not be Joseph Kony or Kim Jong-Un, but you are contributing just as much to the fear and hopelessness on Earth by becoming a part of it. And you are short-sited. The world is certainly not perfect, but it is also most certainly getting better. The most knowledgeable people on this planet are optimistic. They understand that horrific things are happening across the globe right now, but they also understand the world's natural condition of progress. These are also the people that contribute most to the progress of humanity.
Sorry to rant. I agreed with your comment for the most part aside from that.