also please learn body and facial proportions and how a head is shaped and how hair works. I see how you're trying to cover up your shoddy linework by making your lines big, sketchy, and thick, but it doesn't work. it's still very apparent that your placement of facial features and basic ideas of the human body are way lacking. I'm thinking you're just starting out with drawing on a regular basis, so my advice is to step away from the anime "I will give people checkmark noses and also they will all have long hair so that I don't have to draw ears or the edges of eyes" style that people get into when anime is the first thing they try to do, and just cover the board, you know? work around, learn how proportions and the body work, and find a style that looks good. you'll never improve as an artist by drawing lines of anime people, all facing the camera at the same angle, all with crazy backcombed hair.
and if you're serious about computer art, I'd suggest a drawing tablet or maybe a scanner so you can trace pencilwork. for most people, mouse art is a lot more trouble than it's worth unless you're shading or working with pixels. some people can pull it off, but it takes a lot of practice.