I run most solos as journaling. They don't have to be deep, just narrate the events, and then assign chances. Most of the time I run the normal system for actions, and roll d6 to choose outcomes I don't control: 1: Disaster, 2-3: Failure, 4-5: Success, 6: Triumph. That's usually enough.

Mythic is, as Tiberius says, a lot.

I've also used Ironsworn, which is a little smaller and more character-beat-driven, which is good for some games, and Changeling esp might fit that.

Or the original thing that got me into soloing, De Profundis, which has no mechanics, just letters to yourself or others, detailing the horrific world you see behind the world.

Mythic GME is a big complex tool. It's not just an oracle. It has spark words and lists for tracking goals and characters, not to mention the variations. It's all to emulate a GM. You may be looking for a more simplified system like One-Page Mythic GME. Or just a simple oracle like Recluse.

Mythic is great but it's not the one solution. If you bounce off it, don't let it discourage you. You have to find a system that works for you.

Good luck on your soloing.