I don't pretend to have a solution, but in my experience people underestimate how much energy can be gained by properly taking care of their bodies.

Everyone I know who has high energy levels takes their sleep, diet (and weight), and exercise seriously. Anecdotally, when I have these locked down, I'm a different person.

Obviously this is easier said than done, but I suspect that optimism is much easier for people covering these basics.

What helps me (and I am by no means perfect): realize that ultimately it doesn't matter whether there is despair, or if you have any talent for the subject, etc. You only have two options: do, or do not. Thanks, Yoda!

Leave every day better than you found it. No matter how small the change.

Start moving.

Unless you are immediately living in an actively traumatic situation - you or your family are gravely ill or you live in a war zone, etc. - all of the despair and apathy is a product of you consuming information that is making you feel this way. I would suggest you immediately stop reading and consuming news, which is overwhelming dire and negative. I would start integrating more with your community, volunteering, talking to people in your vicinity, trying to become more grounded into actual reality.

If you want to see negative, demoralizing shit 24/7 it's right at your fingertips. However this is not your reality, and not the reality of most people on earth.

Give me a lever long enough and a place to stand, and I will move the world.