I've seen bedrooms where they have hung curtains behind the headboard that cover the entire wall when trying to hide an asymmetrical window (easiest idea + still allows access to use window if you want).

You could spend the money to have the window removed (if it isn"t needed on the outside of your home) with drywall - OR - you can leave the window - but remove the trim/casing and have drywall added over it. You can make it look as if it is still a functioning window on the outside - but have the wall be blank inside your bedroom.

Curtains would be the least expensive and disruptive option. Make them the approximate width of the headboard. Use a coordinating fabric with the bedding and rugs.

Rod close to ceiling; choose white lined draperies (Amazon has some good ones); match the bedding to the white of draperies and wall. I think centering the bed should allow for two small bedside tables and lamps.

Paint the window trim, the closet door and that trim the wall white, but in semi-gloss paint.

All that said, it looks like the bed could fit on the three window wall. You could do the same treatment and because you will need a few panel to fit the width of the wall, when you do open windows, just slide the drapes open to get fresh air.

You don't mention the fan; if you don't need it, replace with a ceiling light (on a dimmer).

Don't forget to paint the ceiling white, too. You can use the same wall paint.

Another thought is to use art to cover the window. To make it work, reposition the bed closer to the wall and just copy this photo...perfect for your color scheme of light gray and white. The natural grass color for the ceiling light, the light wood framed art...

https://www.etsy.com/listing/1345208653/grey-white-bedroom-wall-prints-abstract

Place a curtain behind your headboard that runs the width of the bed or slightly larger. It doesn't have to be white. It could pick up on a color in your bedding or coordinate with another element of your room.

I'd paint the ceiling the same as your wall color to make the room feel more cohesive - the wood breaks it up enough already.

Say more about your style, tastes, what you are drawn to and we can give more ideas about the room.

I was concerned if I added a curtain behind the headboard then I would have to add a curtain on the larger window as well. And, that area becomes tight to walk past to the other side of the bed and we have a great view from those larger windows. So, if you could let me know your thoughts on whether curtains would have to be hung on both sets of windows.

We are going to paint the ceiling white like the walls. What is not shown in the picture is another wider closet and oak dresser right when you walk in the room. So, there is a lot of oak and hubby is adamant about not painting any wood the color white.

As far as decorating style, I'm pretty simple. Took a quiz and it told me organic modern. I have some color in my house but mostly like it simple in shades of beige with some pops of color. I'm adding a picture of something I purchased that I thought I might hang somewhere in my room. I was thinking of going with more of a neutral bedding but finding ways to add some of the colors in the photo. The gray chair in the room will probably get a slipcover/or a different chair that could potentially pick up one of the colors in the picture.

Although, I'm open to suggestions for a picture as I typically lean towards florals and it might be time to try something new. But I liked the muted tones with the blue. Thanks again for your suggestions!!!!

BTW, this photo was not taken in the bedroom. But, wanted to also show you these curtains to see if these might be okay to have behind headboard or if they should be more formal? If I go curtains route in bedroom, not exactly sure what type of curtains. Thanks again!

You might try just hanging artwork asymmetrically. With small wall mounted nightstands and wall sconces, the entire wall behind the bed is a feature. Sconces don’t have to be hardwired. You can use LED bulbs that are operated with a remote.

I have wll to wall drapes behind my bed to cover a windows way near the ceiling that we do open from the sides but I don't want to see them. I love drapes in bedrooms and we also have a large doulble window which I did in matching drapes I give a bit of a feel of luxury and keeps out the morning sun for my hubby.. The headbord is quite pretty but the bedding is pretty sloppy and no connection to anything else in the space . I usually use the bedding to set both the style and the color scheme for a bedroom. Our drapes match as clse as possible to outr wall color too thenuse different bedding with a bit of the drape color in accent pillows at different times of the year , this was in the summer the accent on the bed had gray in them,