I completely understand. Every time I try some new device or tablet or pen I have to struggle for hours to make it feel "right" for me to even enjoy it. Treat yourself with the moments you enjoy, like rendering or inking for some positive reinforcement.
I try to make my digital art feel like traditional art while I'm making it. So it will sort of inform you like a style guide. Ink, pencil or charcoal and marker.
Here's a tip for your line art. Start thin with all the detail and outline. Then try to separate the elements with some darker lines, and some occlusion shadows in the corners to enforce the overlapping of the parts. Your lines were a little close in weight all over. So it is hard to tell the difference between the sections of cloth and armor.
This will also will help you organize your shape designs for the clothing and make it stand out clearly. Hope this helps you enjoy your digital. Not quitting is the only secret.
I dont want to hi-jack your thread. But I hope this gives you some encouragement. Post anything you need help with in the critique section anytime.
