I've had many dark thoughts about the world myself, but as I'm coming out of depression overtime, the outlook on the world changes.
I will share my dark thoughts and hopefully some useful wisdom out of it:
Sometimes during my moments of depression, I feel it's because there is something wrong with the reality we live in - we are not united, people say as they want for their own sake, people meaninglessly seek pleasure. There is poverty, war environmental destruction, global warming... A reason nothing is solved - lacking unity. We are all human, yet each of us is driven into his own goals. The internet is a great contributor to this mess, too.
I've come up with a guiding sentence to such deep depressive moments, to counter them: "No matter the dark thoughts you have and dark things you see, the human raise will always prevail. No matter the vengeance, the wars, the destruction, it will always prevail."
Government executive actions are a complex of systems including so many people, so much intelligence beyond one person's reach. Other than expressing thoughts and feelings there's hardly something you can do about it. You're one person out of so many. If you can't do anything about it, just live your life as others do so innocently!
Yet... another piece of advice I can give you is to be compassionate to your depression. The depression is also a kind of feeling towards life.
I personally have no problem fighting the odds and fighting what is wrong. But that requires preparations, mainly unity.

I don't know if it's much advice... but you can write everything you feel about the reality we live in. It may be worth for people to know how others feel, and accept negative feelings for a change, not just all blossoms and happiness.

As for practical advice:
There are many things that have helped me personally. One is exercising, second is natural medications - Stabillium 200 for stress, and St. John's Wort (500mg) for depression (specifically mild-moderate depression, mild anxiety and mild ocd).
I am not very pleased with having to use an AD (St. John's Wort), but it's natural and non-chemical, and I am eventually planning on improving my diet and plan to treat depression by consuming better amounts of vitamins and minerals, be able to gradually take exercise as a habit since I've always tended to fall from it...
I merely use the AD as a tool, not as something I have to depend on.
It has been described in articles that lacking vitamins and minerals such as vitamin D and Iron can contribute to depression, too.

Though I may not be the best example since I have mild-moderate depression, I'm telling you this to show you there are so many ways to make yourself feel better.
Since it's a major depression, medications can greatly help, and you don't have to take them forever! Medications are taken for short-term for mild-moderate depressions, and usually with therapy along the way. Major depression however may take more time to heal. Keep in mind that suicidal idealization does not necessarily mean major depression.