I have a concept (I did not measure the pieces) so see if this might work. I added a sectional with ottoman, a butcher block kitchen island, a round dining table and chairs, a TV, a bed, nightstands, desk and dresser.

In your shoes, I might sell your sectional and get a regular apartment-sized sofa instead. I'd put the wardrobe on the wall in the bedroom area that's perpendicular to the window wall and have the headboard of your bad opposite the window, leaving enough room for the wardrobe door swing. (Where the wardrobe is placed now would force you to go all the way around the sofa to get to the bathroom from your bedroom.) Put the desk next to the bed closest to the living area and use it as a double duty desk and nightstand. Put the sofa back facing the kitchen and put a rectangular narrow dining table abutting the sofa. That will give you room for a small lounge chair at a 45 degree angle opposite the sofa and facing the fireplace. Find dual purpose furniture for more storage, e.g. a storage ottoman for a coffee table and/or a storage bench for the foot of the bed.

I would not do a sectional. Sofa and an ottoman and some C-tables to use at the sofa.

Okay, as suggested by @Sabrina Alfin Interiors here is sofaback facing kitchen with dining table abutting the sofa plus a lounge chair opposite and at a 45 degree angle facing the fireplace. Wardrobe and desk in bedroom/

Here suggested by @Susan Davis is Sofa facing TV with dining table in kitchen with open prep area and chairs nearest the dining area.

I like your idea of using the table as a workspace. I have a lot more room, and that's still what I do. I also curl up on the sofa with an end table (beverage) at times. And I like using my ottoman as a laptop holder too. Those three options are plenty for me. Do you need storage for a wireless printer somewhere? 

I also like the idea of having stand-alone shelves as a divider to give your sleeping area some privacy. Unless you are in an earthquake prone area. Regardless, furniture ties are a good idea.

I am in the camp of purchasing a small sofa or loveseat instead of a sectional. If you have lightweight kitchen chairs, you can move one or two for seating if you have company over. Make them nice enough for that dual purpose. You don't have to have four chairs. If you do, they don't have to match. Pairs of matching chairs are enough. 

Consider shopping for outdoor furniture for your apartment. Lightweight, less expensive, very nice quality these days, can be hosed down if badly soiled. Best thing is they can be repurposed to the patio of a house someday if you are young. If you are old, the lightweight aspect is of value... And someday your kids might repurpose it for their patio. Just a thought... Might not be right for you.

I've lived in many small spaces and sectionals are not your friend. Get a sofa with movable, ottoman - not an oversized one! Table as a desk and extra counter space is great.

Storage ottoman?

As said above, storage furniture is your friend. Beds now make use of the under bed space with drawers or gas lifts. furniture with a small foot print also helps to make a small space feel spacious. If you look for items such as sofas with legs, it keeps things from being low and heavy. Kitchen table doing double duty as prep and eating reduces the number of pieces in the room. Using the wardrobe as room divider will give you a room, but it might feel more spacious with the bed in view and the robe against the wall. It’s moveable so you’ll soon find the best spot!