i would say, choose a theme just for that space and work around it! for example: maybe "asian" theme! paint the back wall RED or ORANGE, have a piece of buddha statue on the top most rack, you can use one shelve to just hold books with some decorative book ends, and instead of the chair, you can use the asian trunck boxes (if you google for asian trunks, you can see what i am talking about! - look for square boxes), this way, you can also tuck those boxes under the desk/shelf when not in use and the trunk could also be a storage for your files - you can also place a floor vase with some bamboo sticks - the asian theme would really work here as your wood is black/brown this would also turn out to be a peaceful writing space - enjoy!

I suggest that you try to find some plastic bins that are almost see-through and fit the space. That would be two for each of the lower shelves. You could pull out the bins to see what is inside and even label the outside. Or you could cut your plywood to fit the space and support it on the built-in shelves with bricks or purchased legs. The problem with this is that things in the back would be even more hidden than they are now. Then for the upper left you might be able to find a set of shelves that would fit. For the top right, I would put big soft things that you can grab and that won't hurt you when they hit you on the head! This might be extra bedding, towels, out-of-season clothes. For children's clothing I like to fold the whole outfit together, so that one doesn't have to hunt for the "matching" part. I think that your cosmetics could be in a small box that fits on top of other bins or clothing on shelves. Good luck. This will take some experimenting, but something will emerge.

loft will be 5 deep and 3 feet from the ceiling it will have a water tank and I can keep other stuff.

Actually the plan ( in black background), the one with measurement is the original one drawn by an architect . The other drawing (3d n the colourfull) is just a plan i drew to have an idea , where to arrange the furniture nd some modifications using a software called MAGICPLAN. That is why the staircase and bed is of awkward sizes, my bad. About the modifications, i have removed the partition between living and dining, have made a space for handwash, storage spaces for one bedroom and in kitchen which is protruding outwards marked with slanting lines in drawing, also extended 60 cm on northern side of the house to make room for balcony for bedroom, more room for bathroom nd work area. Do u think there is less space for storage, like to fit in an godreg alamarah somewhere??