That's a tough one. If more change is possible, I'd consider putting the bed on the wall where the dresser is now. Put the dresser under the window. Eliminates the problem. But if you want to keep the bed where it is, I'd consider doing a Roman shade that matches the wall paint -- it would all blend together when the blind is pulled. But I'm thinking you don't want the window covered, so . . . I got nuthin.

Well, maybe not nuthin, exactly. Shutters that would add some width to the whole scene?

I'm in the move the bed camp -- either to the wall where the dresser is or possibly below the sloped ceiling (depending on height). I've had beds under windows, so it's not thhat I don't like that look, but this room doesn't support that look, IMO.

If the bed needs to stay on that wall for you, then I would hang curtains as high as possible and to the outside of the window -- don't cover any of it. Then use a shade for privacy.

But white instead of the blue drapes:

Or this: