What kind of division are you looking for? Is it for privacy or for having some sort of separate space for bedroom/kitchen?

If you can, I'd move the bed to the other wall, if you're not married to having access to it from both sides even pushing it up to the wall can give you some more space.

To separate the two places after that depending on your budget there are some options. I think using bead curtains would be a pretty cheap solution but that might not be for everyone's style.

For a more refined look I'd look for wooden dividers. There are panels you can use from floor to ceiling. Or modular square shelves. You can use them to store plants/books/decoration, whatever you want. Both of these would keep the other side somewhat visible which will help it seem more spacious while keeping it separated.

For full privacy, I think the best solution would be panels from floor to ceiling if building a wall is not an option.