The thing that sticks out to me at the moment, is less the anatomy and more the line quality. Curves can be curves, but if they are accomplished by a bunch of disconnected strokes, you're going to have some problems with how they read. Things right now read as very stiff even though i see plenty of curves. A curve drawn with one stroke is going to look a lot better than one drawn by moving the stylus (i'm assuming you're using a tablet) back and forth, slowly toward the end point, which is what i'm getting here.
The tail looks okay anatomy-wise, but it doesn't flow well because it's not one solid stroke, or at least it doesn't read as one. And flow is everything in something like a tail. I'm noticing pressure changes, there's a lot of jitter, etc. You want to be able to see pressure changes happen in a way that makes sense. The stroke should feel like one smooth line, which is usually drawn semi-quickly and if possible, with one movement.
A blue line layer is where most of your sketchiness will be, so you have a guide for where your lines should go. This will allow you to give a stroke a few shots which will be fairly similar. It's why people use Ctrl-Z a lot. Once you have your blue line, a stroke takes a second and if you mess it up it's no big deal to retry it.
Really look into ways to develop line confidence, and how to make your drawing tool make smoother curves. It's going to be a lot easier to discern the problems with anatomy and things if the lines are of better quality.
Also looking into hair will be very helpful for you. Hair is really simple but you have to study it. Starting with a thicker, pressure-sensitive brush and working with the broader shapes of it will make it look much better than if you use smaller strokes to start. You can add the marks of single hairs in later, but working only in thin strokes will make the hair look very thin.
I hope this helps out. It's definitely, to me anyway, a bigger problem than the anatomy though that has it's issues as well. But these tips will help you retain your practice a bit better because your muscle memory keeps it as long, single strokes and it'll get much easier quicker than retaining that information as a bunch of tiny strokes.