Hello Yukino, I downloaded your file and sure enough it gives my MacPro the spinning beachball of doom. I have to force quit Blender. Next, I opened the default scene, deleted everything, appended all objects from your “char head5_revised.blend” and all of your reference empties and sculpture appeared. Yay!
So I tried opening your original file again and the same spinning orb of non responsiveness showed up…… but as I was typing this message your file did open finally. It is in sculpt mode with the bangs masked.
So I suggest giving the “Append” method a try and continue from a new blender doc with all of your original items appended.