First, I think your bed is too big for that small space. It's not so much the size of the mattress as it is the proportions of the headboard and footboard. I'd probably go with a simple upholstered headboard and leave the bed where it is currently.

It’s always nice anyway to see the bed directly as you enter. Measure all of your furniture and add dimensions to a floor plan and 1) if headboard suits being under window, place there, coordinating window treatment and bedding. 2) if you have two nightstands, maybe not add one on the left for better closet access, or use two small ones. 3) assume you have a dresser and test on both walls where their bed is located.

Since you have a king bed, it will depend on the dimensions of the space and the bed. If you bed is the one pictured, it seems much too big for the space. Below area a few bedroom designs of ours to help you more:

Parisian Elegance · More Info

Parisian Elegance · More Info

Modern Farmhouse Rebuild · More Info