Photography is a lot of things. Painting with light, capturing moments but, most of all, it's actually seeing the world. Pick up your camera, and go for a walk, and what you'll find is that when you get home, you'll be a little more upbeat. I guarantee it. It really can stave off the blues.
I've learned a lot since I picked up a camera for the first time but the biggest thing so far is that this is a place where people's effort lives on. Almost everything you see in America these days is a reflection of somebody's purpose. From the tallest tree in a city, to a park bench, somebody put thought into the placement of that object. Go to the beach, and you'll find that the sand was placed there by someone, and they continue to maintain it for you. Streets are cleaned daily, sidewalks get repaired, stores are remodeled and flowers are planted and somebody had a purpose in all of it. Farms are the epitome of purpose in nature. Parks are another example. Roads and railroad tracks... somebody had a reason to make it the way it is.
Most of all, when you consider the purpose in all of the things around you, the world becomes just a little more beautiful. This was all done for you, in this moment.