Hello, everyone

I try to bake sandwich bread but can't get the right texture. There are various sizes of holes in my bread and the structure of the sliced bread is quite loose, when I sliced the loaf, there are many little bread crumbs falling from the surface of the sliced bread. My recipe are 400g white strong flour, 240g water, half teaspoon of yeast, a little bit of salt and olive oil. I knead for about 15 to 20 minutes and the dough can pass windowpane test. First rise for 2 to 2 and a half hours and second rise for 1 hour.The bread texture I want is uniform little hole and the bread structure would be stronger than what I have now. Does any one have any idea how can I do it.

Looking forward to your replys.

Thank you!