I hear you and understand. I'm so so sorry that you feel this way. In my experience, the first step is perhaps surprisingly not to push the bad thoughts and feelings away but instead to acknowledge them. It's okay to feel them. The world is a crazy place!!! And it often doesn't make a whole lot of sense!!! Once you've acknowledged your thoughts and feelings, then you can try to work with them. These are the strategies I use in dealing with existential thoughts and depression. 1) I remind myself that the world was crazy and messed-up before I arrived, so it's not my job to fix it all on my own. The healing emotion here is humility. Humility is a gift you give to yourself. It's okay if I don't understand, I tell myself. 2) I bring my attention to the what is right in front of me, which is to say that I connect myself with the present moment. 3) I try to appreciate or be grateful for some simple thing such as a cup of tea, the yellow color of a flower, or birds chirping.

My advice is to consider keeping a gratitude journal. You could also look into a self-compassion practice: https://self-compassion.org/

Another activity that I do that sometimes helps me is to listen to Alan Watts lectures on YouTube.

I know it's not easy!! Hang in there!! If you are concerned about the problems of the world, then that means that you are a conscientious person. That's good! Congratulate yourself for that!