Preheat your oven to 350°F (175°C) and lightly grease an 8x4-inch loaf pan to prepare for baking.
In a large mixing bowl, combine the sugar, butter, eggs, and lemon juice, beating them together until smooth and well blended to create the bread batter.
In a separate bowl, mix the flour, baking powder, and salt. Gradually add this dry mixture to the egg mixture, alternating with the milk. Gently fold in the blueberries, walnuts, and lemon zest, ensuring everything is evenly incorporated. Pour the finished batter into the prepared loaf pan.
Bake the loaf in the preheated oven for 60 to 70 minutes, or until a toothpick inserted into the center comes out clean. Let the bread cool in the pan for about 10 minutes before removing it.
In a small bowl, mix the sugar and lemon juice until fully combined and smooth to create the glaze topping.
Take the bread out of the pan and drizzle the glaze over the top. Allow it to cool completely on a wire rack.