I honestly think you would be better to hold onto your money and keep saving. I don't think that a couple of thousand will make enough of a difference, and you will still be disappointed, and it would have to be redone in a couple of years anyway.
If you cannot face doing nothing (and I have lived with a kitchen for five years that was falling apart and no longer had doors on cupboards so I do know how you feel) then I would try to take a longer view and if you were to do anything I would do the building work, so that you feel half way towards new kitchen. So decide where you want to end up and implement first half of plan.
Do you want the kitchen/dining room to be an open plan space longer term?
I think you could lose a window and the wall as the light to the dining room is actually cut out by the wall, rather than too few windows. You have got electric not chased into the wall just to the right of the boiler,
feeding the boiler controls, which are now adding to the difficulty of using that wall, and you need 1metre clearance above a cooker, so cannot put cupboards on that wall.
Knock down dividing wall, and make good. Get rid of dresser, because they do not give good square footage of storage for foot print. Buy two lovely old tall pine cupboards, or get carpenter to make them. Paint them if you don't like pine. Together they will take up the floor space of the dresser but give you far more storage. One has plates, bowls, cups, cutlery, glasses, mugs, serving dishes, Tupperware. The other has all baking stuff, bowls, ingredients, metal trays, food processor, bread maker, scales, even saucepans, frying pans etc.
Clear all your spice jars, Kenco jars etc out of the main kitchen and into these cupboards. Clear the walls of the kitchen of spice racks, shelves, clock etc as they make it look much more cluttered.
As someone previously said, get rid of cooker and do oven and hob, B & Q is you friend here, I have bought several sets of stainless steel oven and hob from there for under £300. They look the business, and have staying power. They don't always show up on their website, so you may need to search, or wait till they have their event weekends.
If you don't need the free standing cupboards in your final scheme they make great hall or toy cupboards.
I think this may come across as a bit harsh, I don't mean to be, but I have been in your situation and it is difficult to see the way to go when you are living with it day to day.
Good luck!