This is the secret hiding in plain sight: you do not need the whole cost of a house at once. You build in phases, paying for each as you save:
Foundation — clear the plot, dig, lay the footing.
Walls — bricks up to window-and-door level, then to wall-plate (roof) level.
Roof — trusses and iron sheets. Now it is lockable — a huge milestone.
Finishing — plaster, floor, doors, windows, paint. The slowest, most flexible phase.
Now the oldest trick in the book: save in materials, not just in money. Every time you have spare cash, turn it into bricks, sand, stones, cement or iron sheets and stack them on your plot. Money in your pocket is easy to eat; a pile of bricks is not. You are saving in a form temptation cannot spend and inflation cannot shrink — because materials only get pricier each year (that is The Time Machine working against you, so you beat it by buying early). Five bags of cement this month, five next month — soon you have a phase ready to start.
There is an old line: how do you eat an elephant? One bite at a time. A house is built the same way — one bag of cement, one course of bricks, at a time.