For whatever reason im not able to see the images you uploaded. But no matter. First thing, dont doubt yourself so much, nobody is an expert at drawing when first begininning, its important to realize that someone who draws is always learning and that its a process. its all about practice, artists that you consider "skilled" are just artists who have done a lot of drawing and gone through A LOT of trial and error, trust me. So its just part of the process.
And when someone says you shouldnt figure out youre getting better, its just that if you draw alot, you wont realize it, but one day youll look back at drawings you did and realize the difference in the artist youve become.
That's really the best way to improve. But the 2nd best way to learn and improve is by looking artists that you like. Look at how they draw and see what makes them good. For me, i love to study animators, specifically old traditional animation because they really have the most experience when it comes to drawing and drawing people. If you wanna see some incredible drawings and craftmanship, i recommend looking up guys like Glen Keane, Milt Kahl, Andreas Deja, Frank Thomas. Glen Keane in particular has a lot of videos on youtube showing how he draws and how he drew the characters that he designed for Disney.
Sorry im just rambling now. i really hope i helped in some form. Happy drawing!