All ur boxes are perfectly drawn. And ur lines converge properly. I dont know why didnt u hatch them. Hatching helps the viewer to focus on front phases of the boxes. And i can see some of ur lines are bit wobble at its end its because u tried to stop ur pen before reaching the endpoint to avoid overshooting, instead lift ur pen when ur near the end point. In the end point u should completely lift ur pen from the paper (like plane take off)

And a tip for perfect inner corner (Figure). This image clearly explains everything about relationship between lines. But it is normal to have inaccurate inner corner. It can be improved