You seem to have a lot of potential but you appear to need much stronger reference material.
I recommend getting art influences outside of animation, comics, anime, ect
Study the influences of your favorite artists as well.
You are already studying the classics such as Dragonballz and other older cartoons.
Add real life as an extra influence to add more accurate anatomy to your drawings.
Study how real people look and human anatomy will become much easier to stylize.
study the muscles in arms, legs, torso and how they fit together.
Study the human face to understand how the facial features connect together.
Study everything until you don't need the reference anymore.
You already built a lot of muscle memory from drawing dragonballz characters.
You will already naturally get better at drawing dragonallz characters but you can always excel farther.
You can also study lights and shadows.
Think about where the light is coming from before adding shadows.
The shadow on frieza's neck and under the face does make a lot of sense.
I seen shadows on the necks of real people before.
observe real life and compare it to anime.
You will notice that a lot of anime uses real life observation in it's drawings sometimes.
You got some really great early work.
You'll create brilliant work with a bit more slickness and refinement.