Start Where You Are
It can be overwhelming when you see where you want to go, and you can see all of the things that need to happen between here and there.
It's even more overwhelming when you can't see all the things between here and there.
Instead of focusing on all of the things between here and there, focus instead on the heading that will get you between here and there. Don't worry about the distance, or the elevation, or the terrain. Just figure out which direction you need to move in.
Then figure out what is the most valuable single thing you can do to move in that direction.
Commit to that one thing, and don't get distracted by other things until it's done.
Then stop. Figure out again where you are and in which direction your goal lies. You might even find that the goal has changed position. Take your heading, commit to your next task, and do it all over again.
And don't forget to look back periodically to appreciate where you started from.
Eventually you'll get where you need to be, though it almost certainly won't be where you originally planned.