This is amazing! God, I really feel the emotion conveyed in this piece.
I'd say just keep practicing. It took me a few months to get to a point where I was semi-ok with my digital work. As artists, I think we are always improving. A piece of advice I'd give is to try out loads of pen types and styles, blurring, and changing the opacity. That's the great thing about digital art, you can go crazy and experiment. Also, if a piece is just causing too much hassle, leave it and move onto something else. Sometimes being bogged down on one piece can lessen your enthusiasm for art in general.
If you use specific software, try looking up tutorials or artists on youtube that use that software or style that you like, to get tips and tricks. I've learnt a few skills that way. I hope some of this helps. I wish you luck on your digital art exploration :)