It's a safe bet that you're suffering from depression, and depression is like a lens
that distorts everything you see and makes it look worse. When you recover, you'll see things differently.
Of course, you're not the only one who has a pessimistic outlook. It reminds me of something somebody once said about the British and Americans - that, unlike the US, the UK doesn't have a national mood. This is an amazing idea to Americans, because our country has the wildest mood swings.
When things are good in the US, we think the good times will last forever and when things are bad we think things will just keep getting worse until Doomsday.
Are you up to date about the environment? Even Al Gore is saying things are looking up - "We're in the early stages of a sustainability revolution," he says.
You have probably seen the movie they show at Christmas time, "A Christmas Story," based on the short stories of Jean Shepherd about his Indiana childhood in the 1930s. Shepherd said repeatedly that his fiction was not nostalgic. There's nothing about the Great Depression to be nostalgic about, he said.
I'm annoyed by nostalgia about the 20th century. The US crime rate in the 1990s, which people think was so great, was much greater in the '90s. The riots we've seen in recent years have been child's play compared to the riots of the 1960s.
About depression, it's generally treated this way.
Mild to moderate depression: therapy, usually CBT, and healthy lifestyle
Severe depression: same as above, often with antidepressant
Treatment usually begins with a visit to the GP, who can give you a physical and a referral. I mention referral because just a bottle of pills is not a very good approach.
The first answer below has healthy lifestyle resources. This can contribute to recovery.The second, under DEPRESSION TREATMENTS, has info about a variety of things that can help.