What should I do when I don't want to die but living has become too painful?

Change your outlook. Stop scrutinizing everything that goes on around you and focus on your own happiness. Do you like art, travel, reading? Do you want to write or learn an instrument? Go for it. Find ways to make your life more enjoyable and stop being so philosophical. Find some activity to volunteer for. Giving to others always get you out of yourself. Since you think it's all fake, just go with it. That means you can construct yourself however you like to play along. In short, just accept it as it is and find your happiness in it.