If you keep doing pixel art you'll get better for sure. 6 months is really not too long in terms of time to hone that skill so I wouldn't worry if 6 months in you still feel not as good as you'd like. Gods my first 6 months probably weren't great at all and I had an art education background etc.

If you feel like you're hitting a wall you want to break through I suggest trying to look at things from a new perspective. One book we had to read and work through in art school was Betty Edwards' Drawing on the Right Side of the Brain, which can break some of the mental assumptions you may make in art.

There are also some fundamental principles or questions to art that can each add a dimension to your work. In animation it's the 12 principles of animation. In art I forget off the top of my head but it's like...

What's your camera angle? Maybe try looking up at a person and they feel more powerful or noble. Look down on them and they seem weak or small.

What's your lighting conditions? What if you tried a different color light? Do you know how to change your hues based on the color of the light? How do you handle multiple lights?

What sort of strokes are you making? In pixel art you might not have a brush but you could emulate roughness or clean lines. Does rough messiness evoke a feeling? Does perfect alignment evoke a feeling? What is appropriate to what you are trying to create? Do you want to make a warrior who's just survived a brutal battle in the mud? Or a knight with resolute intent to never be stained with dishonor?

Anatomy. Get a pencil and draw human or animal musculature. What happens if you use that knowledge and try to create a creature by figuring how that anatomy would blend between a human and animal?

Roll the dice. Pick 3 different types of things at random out of a hat for example....animal, terrain type, gemstone. Ok you got worm, tundra, amber (how could amber tell a story about a creature or place? amber traps creatures in goo). Maybe you got lion, sea, jade or mouse, swamp, opal, who knows.

Emulate a style. One exercise we did was to emulate a style of another artist. What if you made a character of yours in the style of Samurai Jack? Flat graphic shapes and fills.

There are also various contests that these sites have that can put things in new light or put down restrictions you might not have ever used.