In my opinion, accepting that things are out of our control is a basic requirement of life, just as we have to accept the force of gravity exerted on us.

I think it's weird and some people have told me I'm crazy, but I tell myself "It'll all eventually work out, but maybe for the worst." I find getting hung-up on if something will resolve in my favor often hinders my ability to influence the situation, can cause self-fulfilling prophecies, and is often more distressing than when the negative outcome is reached.

I also consider our insignificance on a cosmic scale, and find a strange comfort in imagining that our problems are just as trivial and irrelevant as ants, and that I won't care when I'm dead anyway.

Finally, if you're experiencing any death anxiety, I've always found a great exercise to be imagining what it was like before you were born. Did you have any pain or fear? Did you wish desperately to be alive? No. You simply did not exist for billions of years, and that is the state in which we can expect to return. That doesn't sound so bad to me.