"What about orientating the desk and treatment 180 degrees the other way?!?! will that work?????" -
Not without using that absorbent in the entire room - by turning it 180, you cause those splayed walls to reflect right back at you which will smear the stereo imaging - and since part of one of your walls is glass, it would be hard to absorb that.
I knew it would be tight - if you stay on that centerline, you might be able to move the desk further away from the door and get past it - that was one of the problems I expected.
If you do orient things the way I drew, try to stay away from a position along that centerline where either your speakers or your head are exactly equidistant from both ends of that line (front to back)
If you MUST do a 180, you'll need to make a movable absorbent panel for the window and completely absorb the rest of the room - it will sound dead as a mausoleum if you do that, which is difficult to work with and the main reason I recommend against it... Steve