On my first game I thought relatively similarly because the rune is right there at spawn, and it pops up on the map, so that's where I headed. Hunting / crafting / camping along the way, and I was also smooshed pretty quick.

Grab your stuff and run into the woods to start re-equipping your gear... eat whatever foods you've got to get your health/stamina up, then snipe at him with whatever arrows you've got after you dodge his range attacks, which are pretty heavily telegraphed. Once he's summoned you've pretty much got to deal with him.

Or start a new map.