Now press ctrl+shift+I/cmd+shift+I to invert the selection. You can see that your selection is inverted.
Now select refine edge from the top panel. Increase feather to 10 pixel. I have written a whole tutorial on Refine Edge tool which might be helpful to you.
Make sure that black is your foreground color. Now fill the selection with black color by pressing alt+backspace/opt+delete.
Press ctrl+D to deselect the selection and change the blending mode to “vivid light”