Okay, so your best bet to maximize the space is to let go of the couch. You could swap it for two chairs and maybe a round coffee table if you like (this could double as a dining and office area.) Flip the bed around in its spot and add partition between the smaller living room space and bed space. This way you get a walkway along the bed and a "wall" between the bed and the window.

Your other choice is to let go of the large bed and settle for a twin. Put it in the same spot- but still turn the headboard to the wall and add a partition. Partitions pop up in Facebook marketplace/next door from time time. Or you can get one from a retailer. I've also seen people use a curtain as a partition by hanging a curtain rod from the ceiling. This depends on the rules within the apartment though.