How do I soften my shadows?

My shadows seem to be pixelated and very harsh, I tried using a much higher lightmap resolution but I can’t get a better result than this:

If I turn off static shadows for everything in the scene, the dynamic shadows look alright but it makes everything too light.

Also, how do I make the mesh overlap seams less noticeable? I’m trying to build a cave and I need to have some of the meshes intersecting.

Thanks!

Turning on “Use Area Shadows for Stationary Light” did fix some of my problems.

Imgur