It's a lot to fit on one page, but you do it cleverly by making part of the panels a part of the black design. Each panel composition is part of a big page design. You can't help but take the whole thing in.
If there is a weak link here it is the first panel. Did you divide this mechanically, estimate, or do it half and half?
Dividing space for given proportions is basic geometry that you can pick up on the fly. Just make up your mind to do it. Your art would be even stronger once you bring up your building/construction skills even with the finish skills. You're already a beast. So, you'd be a monster!