Cool perspective!

Lookin good, you have the right idea. Moving forward, try to tighten up your lines a bit -- if that means moving slower and spending a bit more time per drawing that's totally fine! Pay attention to the curve of the form and try not to let your contours get too flat.

I think your boxy main issue is that your convergence for all of the parallel lines are going the wrong way. They should be converging towards each other but in a lot of your boxes they're moving away so they don't look like true boxes. You could try practicing 2 point perspective with vanishing points to get a feel for the boxes, and then use those boxes as reference and draw them free hand!