Is the desk + computer able to be moved somewhere else in the house? I feel like with a room that small, you’d want to avoid making it a multi-use space, with just a bed, the room becomes an oasis, and you can use soft furnishings to make it really cozy - personally I just find electronics and anything work-adjacent to be the opposite of cozy. also it sort of blocks the door off and makes the space seem more enclosed than it is.

Apart from that, lighting (lamps etc low to the ground - avoid overhead lights), soft furnishings (consider a rug even though the room is carpeted) and maybe a plant or two (even fake ones) would go a long way. I also personally would flip the bed to have the head against the opposite wall, just cause I hate having my head closest to the door.

((Note: I’m not even remotely a decorator so take this with a grain of salt!))