“Let Fate find us prepared and active. Here is the great soul — the one who surrenders to Fate. The opposite is the weak and degenerate one, who struggles with and has a poor regard for the order of the world, and seeks to correct the faults of the gods rather than their own.”SENECA, MORAL LETTERS, 107.12
You can’t fight fate, and that’s the straight truth. Many have tried — an exercise in futility. None have succeeded. The universe is going to unfold how it’s going to unfold. Life is going to happen how it’s going to happen. You are not in control.
What you can do is align your will with fate, so that you’re never disappointed. Adapting to what is going to happen anyway is the surest way to remove anxiety, as you’re no longer trying to dictate events which are outside your control. Even better, you could come to love fate — amor fati. Surrender to it, fully.
At the very least, you should be prepared so that you’re ready for whatever happens. You can’t determine (or even know) what’s going to occur, but you can stay active and prepared and adaptable, so that you’re not overwhelmed.
The worst thing you can do is to try to “correct the faults of the gods rather than [your] own.” Accepting that the universe can’t be altered, but you can… well, that’s powerful when you finally realize it. You can’t change the world to match what you want, but you can change yourself to match the universe. Try that on for size, instead.