Antidepressants don't fix existential dread. They manage serotonin deficiencies. That's a hardware issue, whereas existential dread is a software issue with no possible solutions.

Death is not ultimately escapable.

You are not permanent; one day, you will go to sleep, and not wake up again.

... but you do have the power to influence the path you walk on the way toward death, the face you'll be wearing, the stories you'll be able to tell, when you finally arrive in the company of the reaper.

You can be secure in knowing that it is not possible to escape this fate... and in knowing that you lived not in an impossible attempt to avoid the unavoidable, but instead, that you chose to tread the path as you saw fit to.

The Greek Gods were said to be envious of us mortals, because our mortality meant that what we did with our one life... was important, and meaningful, in a way that nothing the Gods ever did, could be.

When you realize that nothing objectively 'matters', to 'the universe'... you are now free, to decide what matters to you, instead.