If you upload some more of your art and studies it will help us know what you have taught yourself so far. If these are the most recent then that is okay too.
Pick a Master
Its important to know where it is you want to go. If you are picking a style master to study from, even if its an anime or manga fandom, you need to study them. Go find how they sketch, how they study, how they take multiple steps to finish a piece. Finish a couple of master studies where you cannot tell the difference between your finished copy and your master. You will learn so much along that path I cannot even describe it. Even if you cannot find how they do it. If you solve all the problems to get to the same outcome on your own, you have understood the theory and bent the technique to your own will.
Long Pose, and Anatomy:
I see no finished long pose drawings that take anywhere from 4 to 8 hour renderings. I also see only construction and no anatomy note taking.
If you are copying poses completely from reference you need to take a couple of afternoons to finish just a long pose some time. Digital or traditional. Finish it to the best of your ability. Take notes as to what specifically frustrated you to get to the end. Was it shading, spacial relationships, overlap, composition, anatomy, mark making control? Go forth and find the answers on the internet to any of those problems. Rinse and repeat a couple times a month.
There comes a point and time that the lack of knowledge of your anatomy groupings for artists will become a brick wall.
If you want to draw with no reference you have to do this. No arguing.
Want to have fun drawing with no reference? This is it. You have to study the bones and muscle groups, not make perfect drawings of them. Understand what bones and muscles do. Here's me studying what the shoulder does.
Start learning the bony landmarks first. Write them down. Then start learning how the Skull, Rib Cage and Pelvis interact. Not what their Latin names are, but their proportions and limitations on their movements and relationships to one another. Then learn the limbs from shoulder, upper arm, lower arm. Then hip, upper leg, lower leg. And for goodness sake, dont stop at the foot or hands.
Give yourself six months for this memorization. Not doctor level anatomy, artist level anatomy. Muscle groupings, and bones.
Knowledge is Power:
Start learning the theories that all artists are manipulating. Not so much on HOW they make their art. This isn't easy to do because not all great artists are teachers, and not all great teachers give the best examples.
To specifically address your query however, I can recommend this book.
There is a distinct relationship between structure and gesture. Steve Huston's book on figure drawing to give you the vocabulary and theory you might need to understand their relationship. Mainly that one cannot survive without the other.
I just made another post on gesture in the critique section. Make sure to check that out.
I hope that gives you enough of an idea of where and how to move forward. Keep posting. And work on some finished line art. Your doing hard work, show it off. Your doing great.
Hope that helps