It isn't bad at all, so stop discouraging yourself!
You could complex the layers further by doing separate ones for line art for example, and giving each (part of the) character a own layer, but watch out for overdoing it and loosing sight of your work!
And again agreed with below, try to work as big as possible. Don't fear to think big, if your PC can handle it (depends on the available RAM mostly) you should choose a decent canvas size, atleast your monitor resolution. I have a 1920x1080 monitor, but I usually make a 7680x4320 canvas, so thats 16 times my native resolution. That way you can zoom in and out easily, and work both on the little details as the big picture! If you want a sharper image, or want to print your art, increase the DPI to about 200/300 DPI.
...Yeah, I'm going to end my ramble here, but please let me know if you run in any other problems! I got plenty of time, so I sure don't mind helping someone out!