Awareness of dire likelihoods and absolute realities is terrifying and depressing. My first recommendation for anyone facing such is to seek professional help - I don't mean this as derogatory in any way but from a place filled with love. This might involve medication for some. That's ok. Some of our brains are not great at handling stresses caused by modern human civilization, whether that's due to a heightened fight-or-flight response, tendency towards depression, or a number of other conditions.
My second is to find a way to compartmentalize based upon one's personal ability to impact these externalities or mitigate their effects.
Third, and probably most important, be careful with psychoactive substance use. Alcohol, cannabis, psychedelics, and others can dull things or provide a brief escape but nothing is free and you will pay for it; if you drink, drink to be merry, not to escape despair and pain.
The goal here being to be able to function as resiliently as possible in both day to day and high-stress situations. We're only human (except for the robots) so, we have a finite amount that we are capable of dealing with physically or emotionally. Being able to keep yourself going and not be stuck in an internal pit of despair (been there, it's not fun) is the bare minimum.
Once you're able to achieve that consistently, see about what ways you can cultivate positivity around you. Anything from being kind to people that you encounter or growing vegetables to taking part in or leading a volunteer organization. Just take it one step at a time and be kind and understanding with yourself as we all have limits to what we can do, as much as we might wish otherwise.
Like grief, this awareness seldom goes away but may be made more manageable. It's ok to not be ok sometimes but, it's important to not get trapped there.