Hey, I get you man, its super hard to learn all those features of the face and make them look good
Well as for the ears, actually it helped me breaking them down into different pieces, like outter ring, and all the smaller parts inside, to understand how they are build. Gave me an instant level up. Maybe try that.
And for the last one, looks good so far, what I just noticed was the gap between the eyes, maybe put them a little closer to each other and maybe make them a little wider.
Btw great amount of exercises! Keem 'em coming