Well, you pretty much have answered yourself here... I'd say work on everything you mentioned, and then see how you feel about it. I'll try and make a few observations anyway:

The bed looks like it's made of metal, and it's just a frame. Try dropping it a little closer to the floor, adding a mattress, and removing the puke stain (can't figure out what else it could be, lol).

The bookshelf would look better if you make it seem like it's more sturdy. As of right now, it looks like it's not flush with the wall, it's too thin for a real bookshelf, and the drawer at the bottom makes the base kinda blend into the floor.

Another thing that looks strange to my eyes is that the colors on the walls seem to indicate that they belong to a darker room than the floor does.

Just keep working on it; I think you already have a good sense of what you need to do

It definitely looks much better.

The bed still doesn't really immediately portray that it's made of metal. It may be difficult to create the proper texture depending on your lighting source. The most common image of a metallic surface, especially a square of metal, is that it's got a sheen to it.

The small table and the bookshelf look good, however they still have an unnatural space behind them. Most people would push their furniture completely against the wall, but I suppose that's up to you.

The shading under the bed is good, but once again referring to the light source, you need to pick one and make it consistent across the room. Will the light come from the lamp? The ceiling? The window? Once you decide that, you can complete the shading for the whole room.

Are you going to keep adding to this and create a whole house?

Well, Actually I don't fell like I want to do anything else rather than pushing the furniture closer to the wall.
I think I'm done with this room.

All your problems are scale related.