I had similar stuggles and am getting better with practice, you will get more comfortable. SOmeone sent me manga brushes and some of those are more comfortable to draw with digitally. I envy your ability with animals. I see alot of talent and seems like youtr working hard to capture the accuracy of the poses. It seems your linework shows you're a bit unsure of establishing and sketching several lines to 'find' where the pose is and have some bold clear linework - which makes the drawing less energized (I am the same way! so i'm practicing anatomy and gestures and am trying to keep getting better too!:P). Also, can i suggest getting familiar with mixer brushes for blending your shadows? It helped me ALOT. I think shading looks best on my stuff when I use bigger brush sizes then clean up where it goes beyond my lines (usually i do this on a layer underneath) And as far as getting comfortable digitally, i actually stopped letting myself do paper sketching for 6 months lol and only digital. Now if i get uncomfortable, sometimes i'll paper sketch to warm up then go back to digital. Hope that helps!
